Travel France to Italy and back - best routes

HI , we are planning to go to Italy in June/July for four weeks, wondering which is the best way to go to/from Italy. We're probably not going to go through Switzerland, thinking we might take the Mont Blanc tunnel on the way (stay in Chamonix for a night, then on to Valle D'Aosta). We want to go to Annecy, France on the way back from Italy, looked at the petit st bernard pass, is this a good route for campervans? The days we're planning to return coincide with a cycle race, the enduro world series - would this mean that there would be lots of cyclists on the route? Or would the pass further south coming from Turin be a better route? We will be travelling north from Genoa on our way back so could take either route. Our camper is 7m. Also any ideas where to stay en route would be much appreciated.
Any suggestions or advice would be brilliant.

The Mont Blanc Tunnel

No real

Had a look at that route, it looks fine not too steep, thanks for the info.



Wont be able to avail of return ticket in mont blanc tunnel, it will be three weeks before we return.

Ps nothing steep on the route we used...it was main roads all the way. The Brenner pass went over 1800 m I think but gradually. Steepest part was back down to Chamonix via tunnel. Also with the route we chose we had to buy v little (expensive) Italian diesel. Our van is 6 berth knuass with ducato 2.5tdi from 1998.

Hymer, how long did you allow for that route- we have 3 weeks at the end of May, thinking 3 days down to Italy from Roscoff, 10 or 12 days there, and 5 days back up to Cherbourg. Also do you think booking a site in advance is a good idea at the start of June?