I had a holiday with 2 DDs, SILs, 3 GC 2 sisters in law in a huge rambling house in the S of France last summer. There were 10 of us, but another family of four joined us for the weekend.
We had a pool (but behind a lockable gate so the little ones could not go in unattended.) We had 2 biggish cars with us, (3 when the other family were there) big enough to accommodate everybody for days out - and …..this was the height of luxury - the best bit was that for the 7 bedrooms, we had 6 bathrooms/loos!
Start looking well in advance, bigger Air BnBs book up quickly and are not cheap . Per (adult) head I think we paid a little under €100 per night .
I would say try not to make it too expensive to get there, eg no expensive flights, remember you’re talking school holidays, and a ferry to eg Normandy or Brittany or Eurotunnel means that those who want to drive can. I would also sure it is big enough all to eat together (so if three separate lodges check they are spacious) and that there are things for all age groups to do.
I’ve also done Forest Holidays in this country with DD, SIL and GCs, not cheap but deep in forests with bike trails and nature trails.
Avoid Center Parcs, IMO too pricey!
