I'm sure the very advanced skiers will be able to advise, particularly as they will have been to many ski resorts already and may be able to make a more appropriate choice.
I would suspect that the best option would be self catering driving across the channel to somewhere like Val Thorens, Les Menuires, Tignes, or maybe even a smaller resort with no cars like Avoriaz. (although it is not that good for experts)
These are all in France. People say it is cheaper in Austria, and Italy, but it depends on what you spend money. Family ski groups tend not to spend a lot on apres ski, so France should be fine.