In reply to Pete_Frost: The latest I've been is 20-24th Feb. But that time conditions were excellent and good for a few more weeks after. I think it can vary a lot from one year to the next though.
I've stayed in both the residences Nigritelles - very spacious apartments with cooking facillities and good buffet breakfasts and the more expensive hotel la Balme which was half board with amazing portions for dinner. I'd stay at either again.