Ryanair do Stansted to Tours, Terry. Cheap as chips to get to the gorgeous Loire Valley, then we can either do you B&B, or a gite for the week, or even hire you our Avondale Rialto 555/4, and put up the awning for you!
We flew to Rodez, with Ryanair, from Stansted. The area around is beautiful and you can drive across the new Millau viaduct.
Another good and cheap airport is Toulon with Ryanair from Stansted, plenty of sites offering statics all around. Choose from the Cote de Azur on your left, and the Carmargue on your right, or the mountains inland.
Don't forget to leave a review of the French and other European campsites you have visited!
...I saw one crazy fare from Gatwick to la Rochelle ..couldnt believe it ..something like 943 squid return ......... must look again!!!!!! Went back to looking at early bookings for ferry crossings! (been to turkey for a fortnight B & B for less than half that fare.....)
I would look at www.moneysavingexpert.com and go to the FlightChecker page for cheap flights. I haven't used it to try and book, but someone recommended it before.