In reply to sethmford:
It will be tricky to hitch hike, I think. There is a long highway stretch to Albertville/Ugine, then a winding road up to Praz sur Arly/Megève and back down to Saint Gervais before the final climb up to Cham, so probably as many independent sections to hitch hike separately.
Did you look at car sharing options on covoiturage.fr? Otherwise, try to spend the night somewhere and get the train the next morning.
