We went through the mont blanc tunnell in 2009. We paid 48e then .........and we were on our own. Signs around Chamonix were sayin tunnel was closed due to flooding but on leaving our site the owner said to go up and they may let us through. Well......they did and it was funny thinking how the day before we had trekked around the top of it and next day were driving under it . MAD.
If you are in Chamonix you may want to give it a day or two. It's a beautiful town and well worth a couple of days. There's a train ride and the ski lifts are well worth a look if your into walking.
We were due to stay overnight on an aire but reckoned it was too nice to just pass through.
We stayed on site 15 mins walk from town centre called Mer de Glace.....N45'56'18.0 Eoo6'53'24.0 a beautiful site with great views of Mont Blanc and a lovely walk / cycle along the river to town centre. The site wasn't cheap but facilities were perfect and numerous walks from the site.....plus that view.
We stayed at Lake Garda but for love or money can't find coordinates of site or it's name.....sorry. It on the southern end of the lake with access from the site onto the lake from site. Around the lake can be expensive to eat out..........but if you go back a mile or so from lake shore you can find very reasonable restaurants and a meal for two .... 3 courses for 25e /30e
I envy you your trip. Hope this us of some use. P. S. Traffic around Turin is mad ......be aware.