In reply to whereisearl:
Hello- I did that in 1990 or 1991 as a student- I bivved and stayed in 2 gites when I got really stinky and needed a wash.
Basically it is really easy to bivvy (or wild camp) on the hill- not so easy in the valley bottoms. I think I bivvied at Col Voza, Col de la Seigne, Monte Saxe, Col Ferret, Fenetre D'Arpette and Plan Praz all without problem.
It is easy to get supplies in Chamonix / les Houches, les Contamines- then there is a bit of a trek to Courmayeur- then a bit of a walk to the Swiss Val Ferret and then again a bit of gap to Chamonix again if you do not divert to Argentiere (or Trient).
I think you only need carry a couple of days food at the most. Alternatively you could take no spare food and eat at huts / gites if you ran short. But this is expensive.
This summer I'm back- but with my wife and 3 kids (8,13 and 15) taking a different approach- staying in gites and huts, and taking only a bit of emergency food. Planning on buying it as we go along. Hopefully we will have very very very light packs.