We spent two weeks in Tignes last year (boys 6 & 9) – couldn’t recommend it highly enough. If you stay in Tignes, you get an activities pass which gives you free entry to pretty much everything there, and Tignes is a year-round resort. Loads to do if you’re not riding (watersports, football, leisure centre, tennis, glacier skiing, archery, horse stuff, skatepark, golf, all sorts) and if you are, the pass gives free access to the lifts with your bike. Not quite as much lift-served terrain as, say, Les Gets or Morzine, but less busy as a result and it does join the Val d’Isere system.