In reply to goatee:
Great trip report; enjoyed reading it and seeing your photos.
Split my time in retirement between Scotland and Nice, so know the Mercantour quite well ( currently in Nice). Haven't done as big a walk as you yet but have stayed in Refuge Cougourde and de Nice.
There was no rain in the Nice area during October ( and, statistically, it is one of the rainiest months); although there has been rain at the beginning of Nov - much needed.
It is a great area for walking.
PS You need a better sleeping bag!