My parents live in Avignon down that way, and they’ve commented how frequently I’ve been popping down there recently 🙂 Never taken the mtb as it’s too much of a slog on road to get there and back, but the road riding’s as good as road gets (without being as good as miles of singletrack).
Usually go up Ventoux about 3 times a year, and usually see a few downhillers covered in mud popping out of the bushes onto the road.
If you take the road bike, climb Ventoux via Mulhaucene (easier than Bedouin in my view), down to Sault, and then back via the Neques Gorges. Lovely long stretch of winding downhill with great views of slabs of rock. There’s tonnes of stuff down there, but bear in mind, the only way back is to ride so I wouldn’t go miles out. It’s easy to do as French tarmac is silky but then there’s the wind … wrong day and it’s murder.
Consider anywhere in the Luberon – Cavaillon to Bonnieux on carless broken tarmac. And there’s the Ardeche too.