Dilemma over potential house move

I would agree - don’t move. As the GD grow, you will not be involved so much, even thought they love you just the same. An hour’s drive is not too bad, if you can find a nice bed and breakfast place near them, and spend long weekends with them.
You need your savings as a cushion, so don’t deplete it.

I went from dont move, to move, to dont move.

How old is GD?
How many more years will you be needed for school run and overnight stays?

I dont think I would move into the potential new house you have found.
Maybe another more suitable one will turn up, if necessary.

If you have a social life, good facilities and a home that suits you I would stay.. as others have said your family dynamics will change and may not include you as much.. It is possible but not easy to make new friends when we're older.. also if you don't spend your savings you could use them to spend holidays with your family..

Calipso makes a good point. I’d stay where I am. DH looked after DGC from birth-nappies, feeds, school run etc. Now in their teens, we still see them, but infrequently because they have their own lives and activities.
What would you do then?

if you have doubts, stay where you are.

If you are happy where you are then I would stay, you are not going to be needed as your grandchild is getting older.

I assume you have friends and a life where you are, I dont think your daughter has thought about them being your only company and entertainment if you move. They may come to resent having to include you in everything.

It's always worth asking yourself the question 'What happens if they move again?' Where does that leave you?
From my own experience with (several) grandchildren, once they start senior school the dynamic changes. They still love you for sure but they belong a bit more to the world and a bit less to you. Which is as it should be.
Good luck with whatever you decide - I think you know the answer