In reply to eivindf:
I have only been around xmas time. For the last 4 years.
The first year it was good for 2 days then a big snow hit all of Provence and we needed our chains to get out and further down to the south of France.
Otherwise chilly at nights, but nice in the day in the sun. We are used to Scotland so any sun is nice. We would maybe have thermals on, but often just lighter clothes or teeshirts. And we wouldn't be looking for crimpy holds. Not that we ever do much.
We have been lucky in that we always seem to hit it just before the big cooling air comes in about end of Dec and cools everything down for the rest of winter.
So earlier in Dec or Nov would be very nice I would think.