Andy
For VFR in france get a pack called VFR Documents in France published by Service de l'information Aeronautique. It has all details of danger areas, rules , frequencies etc. It is now obtainable in the UK.
Flying in the airways at the appropriate VFR levels, different to UK quadrantal rules,eases the planning problems ref restricted and danger zones and airforce low level high speed routes which must sensibly be avoided.
The Mistral of the Rhone valley should not bother you as it is considerably east of your route, but the winds I mentioned, Carcassonne on south, are equally fear and fuel consuming.
Good idea to enjoy the trip where ever you have to stop over for adverse events.