From Lons de Saunier, take the slow paced route, national road to Orgelet to Oyannax, glacier valley, with plenty of camping by the lakes and rivers in a gorge .
From Oyannax, then to Nantua, this was my shortcut to Italy to avoid some of the motorway tolls.
Even though it is a weight limit, I never got a tug, for a camper van, no worries.
Some villages were 3.5 ton limits, the rest is 7.5 ton limits, back then the Eastern European hauliers were using it .
For Italy, headlights on in the day, enjoy the quality food and meals, once you use the Italian toll motorway, Lavaza coffee is everywhere.
The service stations have good food.
Going off route on the free roads in rural areas, restaurants have odd closing times, if you see lots of lorries parked there, then it is a reliable place.
Keep plenty of cash, in case the bank cards do not work at the toll booth.
In rural areas, the signs are not good, and easy to get lost .
Enjoy Lake Garda.