Hi, i’ve been a few times as friends have a chalet in sainte foy, well la thule and there’s tons of stuff. As said you can ride down from Tignes all the way to Bourg then up to Les Arcs (much better than Tignes imho) if you like which is great. I thought Tignes was ok but the dh runs get boring quite quickly though check out the more xc stuff to the right of the bowl, oh and lifts were free last year too for bikers.
Sainte Foy itself has some great trails, plenty of wooded singltrack and they have a 4×4 uplift in summer too.
If you need accomodation let me know
Might be worth getting in touch with The White Room in SF or Trailaddiction in Les Arcs for a guided day to get some local knowledge to save you time hunting stuff out