Hello,
I live in the French Alps, just up in the mountains from Evian, You can wild camp everywhere up here. Annecy is a really nice place and go to the far side of the lake plenty of places to camp. Also try the Route de Grande alps really stunning scenery.
I live in a place called La Chapelle Abondance and we have at least 2 places to park here free, if you manage to get up here mail me.
I would also suggest Aix Le Bain very pretty. Just look them up on google.
We drive back to the UK a few times a year and have found coming on the A roads less expensive, we go through Bessason.
Have a wonderful time.
If you need more info mail me.