What approach to take?

i would go for christmas and then help all you can ,then maybe in a quiet moment talk to her. say you might be able to help instead of her shutting you out,. i agree with the above ,be kind and gentle if she gets up and huffs up ,just carry on doing what needs doing..the children will help with the awkward gaps./go for a walk all of you after christmas lunch .fresh air clears many things.....good luck...

Answering one question - we have not seen her since 27/12 last year. We wanted to go to the UK in the summer, but did eventually had to abandon the idea, as it was our suggestion : nor did they come here.

I agree with Maggiemaybe. I also think it is a very good sign that you have been invited! Remember this and look forward to seeing the children and go there without any prior agenda. If she is uncommunicative, don't force her or strain the atmosphere. She may have something in her background that has left her with a terrible fear and difficulty in relaxing with our generation. Give her space if necessary. Make sure she never feels criticised and just try to be relaxed and happy and calm.
I do hope you will have a truly happy and blessed Christmas. I am so glad she is having you to her house, it is such a good sign.

How often have you seen her in the last nine months?

I would stay in a hotel and arrange a break on day 2 or 3 so that DG can relax with family. Also maybe arrange an informal meal out - somewhere used to children so that there’s no strain, and/ or a panto unless they are going akready - if any of the grandchildren are too young for that you could perhaps look after them while parents take older ones, or, you take the older ones yourself. Obviously need to talk with son as you will need to book well ahead. It could be a turning point - good luck.

What a predicament. What was the relationship like prior to 9 months ago? Can you think of any contact that may have triggered an issue?
Is it possible to ask your son general questions such as “ Are there any subjects to avoid?” Or “Is there anything we can do or say that may make things easier/better?”
There are some great suggestions posted here. I definitely think you should offer to stay elsewhere if that appears reasonable, allowing them to make the decision.

I'm with Buffybee on this. You long to see your GDs so do just that.

Be kind, thoughtful and interested in the family activities. Behave as if nothing is wrong and coast over any odd problems. If you expect to have no trouble and give none you will probably be welcomed - they must have wanted you to invite you - and you do not know what has really gone on. If you seem to think all is well it probably will be, so don't ask, she will tell you if she wants to but she may just want o sweep it under the carpet / let it drift into the past, especially if she has done some thinking and realised that she has got the wrong end of the stick somehow and is embarrassed to have misread a situation.

Good luck.

I'd stay in an hotel, bnb or airbnb, just to allow them to have some private time. I'd hate to hear arguments between husband and wife, even if they were in another room or even in bed.
Besides that aspect, a frosty atmosphere can put a dampener on the most joyous occasion and 4 days is a long time to spend under the same roof as a silent DiL.
At least, in an hotel, you can go to bed when you please and aren't 'having to be entertained' 24/7.

Just go and get on with it.

Well said to BUFFY! which makes perfect sense to me. Just be 'yourself' .... That's all we can be.

I prefer not to stay with anyone now and always book a hotel. Makes it more relaxing for everyone and I like an escape route.

I wouldn't confront DIL on anything. She's not talking ....
Fine! Just be yourself and make a conscious effort to have fun x

Mmm, you point out that you have given a substantial sum for improvements to their home, then point out that you do not want to stay elsewhere. Could it be that your dil now thinks that you feel you have bought the right to stay in their house because of the money given? By making that remark on here it makes me wonder if you do think you have some rights over staying?
It would make my blood boil if my mil and fil had given me any money (they never did) then felt they somehow had a right over my home. Think back to see if either you or dh have made any comments about the money, whether in jest or not.

Evianers, that is such a difficult situation. If you don't go, it might be seen as you're not interested in Gc. If you do go I think you will feel extremely uncomfortable. Would there be any way of a compromise where you go but either stay somewhere else and just spend a few hours each day with them. Or just go for a day, even if it is a long way. You could stay somewhere else and it would put a lot less pressure on you and dil.
CrazyH I'm glad I'm not the only one, got exactly the same retort.

I would go just to be with my gc and just be my normal cheerful self, include her in any chit chat but ignore it when she doesn't reply or talk back. Hopefully jour says will be so busy with our gc and son that you won't notice her not talking to you much.

An Airbnb 'locally' might allow you distance, independence and somewhere to see children outside their own home yet not in a public place. You can cook. You can invite them all for a meal!
Have used them often and never had a duff one yet.

I'd be inclined to find out what the problem was first before having to endure 4 days of tension------which is no good for anyone's health. The atmosphere could be really strained and children can also pick up that all isn't as it should be too.
I'd definitely go once there's been a resolution.

We live in a different country to our DD and family and in the past found it more comfortable to stay in a hotel within walking distance. We ate all our meals and spent all our days with the family, but a bit of space is good for everyone especially at fraught times like xmas.

In your situation I would talk to DS say how you look forward to seeing them all, and would it help if you slepted in a hotel. It is then up to your son and DIL to decide.

Whatever your DILs problem is, I have found that time is a better healer than confrontation if you value family harmony, and if she struggles with relationships giving her some space whilst enjoying your time with GC and son may help build a bridge.

I find it very odd that your DS hasn’t told you what “it” is, how can anything be resolved, explained or apologised for if you do not know what you are dealing with. Surely he wants peaceful and healthy family relationships ? As others have said tho, your granddaughter is the most important thing here ... good luck.

I am with * buffy* & janea here! DS has probably negotiated this with his DW. It is an olive brach. Be bigger and stronger by accepting it with good grace. Say how fab the house looks..DO NOT MENTION THE -war- MONEY... It was,a,gift and is not anything to do with you how it is spent nor buys any special status! You could say thank you we 'd love to come and stay with you. Can you book a local place for dinner / lunch for us all one day..we would like to say thank you for accommodating us.

Oh go and act as if nothing has ever happened perhaps your daughter in law feels worried or ashamed that you’ve paid for so much, perhaps she didn’t want to be beholden to you maybe that’s what IT is who knows
Id be upset if my family stayed in hotels unless there was no room in my house
Go enjoy the grandkids, be pleasant to the daughter in law if it’s not returned, don’t worry it’s only a few days

4 days is a long time and I definitely would not feel comfortable staying with the family unless I felt wholly welcome and wanted. I would need a bolt-hole and would book somewhere to stay nearby. You could tell your son and DIL that you'd love to join the family over the festive season but think it'll be easier all round if you stay at an hotel.
Then I'd follow the advice of other Grans and be as nice as pie which would be easy knowing that there's a bolt-hole to retreat to if the going got tough. Good luck .

Absolutely agree with Grans urging you to accept the invitation. You will regret it if you don't go; it's an olive branch although you may think it a small one. ChaosInc's suggestion of giving your dil the opportunity to suggest a local hotel, BnB or AirBnB is a good one so that your dil has the choice in case she had felt obligated to have you stay in the house. Sometimes it can be less wearing for all parties if the charm offensive doesn't have to be 24 hours a day and there is some opportunity for time out. Christmas is a notoriously difficult time for family relationship tensions so make it as easy as possible for everyone probably including some tired and over excited grandchildren.

I would also opt to stay in an hotel if you can do so without causing offence. I suspect your DIL would be secretly relieved. That way you have somewhere to retreat to and you each have your own space. 4 days is a long time to spend together over the festive season even when there are no underlying tensions.

Whatever caused the original rift, and whatever the rights and wrongs of the situation, this is a massive olive branch and an opportunity to try to repair the relationship and see your grandchildren. Be as sensitive and kind as you can and try very hard not to let any underlying resentment show.

Like previous posters, I also wonder if your gift of money for the home improvements is a factor, either directly indirectly.

Your DIL sounds like a difficult person, maybe as a result of her relationship with her own mother, it probably doesn't do to speculate, but smile and think positive thoughts - you will be with your son and beloved grandchildren at Christmas.

Not knowing how big the house is, it is difficult to know whether an offer to stay in a hotel would cause further upset.

We always stay with DDiL's mother when we visit our DGC because their house is small. If it is not convenient to stay with her we book a B&B. If they had a large 4 bedroomed house, it would be different.

Just to clarify, I was not suggesting that the OP should stay in an hotel, but that she offers the DIL the option for her to do so. Essentially, if played correctly, you are setting out well in advance that the olive branch invitation has been accepted in the right spirit, and wantthatmake clear that you are taking the "their house, their way" approach.
Of course you hope that she will reply with confirmation that the invitation obviously does mean staying with them!

A quick google shows 4 flights a day into Luton from Geneva, and that was just checking one airline, so I would politely suggest that there is room to ask what times work for them.
As another poster mentioned, you catch more flies with honey than with vinegar!