In reply to Jonshef: You've got a week, and you want to spend 4 of those days driving to the south of France? Not my kind of holiday! Barra to the Butt of Lewis is a similarly driving heavy idea. I did that recently and took nearly 3 weeks to do it *and enjoy it*, with a full day of driving at the end to get home. Font is a decent idea, but it isn't a road trip, it's just a there and back.
If you want a week with plenty to see and do, and wet weather alternatives, try the south west. The schools have gone back and the roads are quiet.