I haven't been in France all that long, and most of the places on your list I have yet to visit.

It sounds weird to say this, given that it's my neighbourhood, but I'm not sure I'd bother with Narbonne when time is limited. Carcassonne, yes. And Nimes and Avignon, definitely. Also, Cannes is lovely, but it's so like Antibes that I feel you could just pick one. That way you could spend more time in Nice, which deserves it.

Anyway, you'll have a blast. A road trip in France is very unlike a Canadian one though - get used to getting hit with tolls everywhere you go!