In reply to gavc0: You need to be a bit carefull if your wild camping sometimes as it can piss people off, but don't forget about the french parking rules!
We stayed in Chamonix last xmas, we parked up in a few different places which was ok. But nearly all the free water supplies were frozen, or were banked out in deep snow (couldnt find one of them!) we did spend a fe wnights in a winter campsite, dumped out water, charged up and got fresh water.
There's usually some aires on the way into resort which are a bit lower that wont be frozen.
The all the aires book is ok, but not easy to use, and not always accurate. Dont forget your hose pipe for filling your water from the taps.
Cheers
Dave