Fattoler, you are a provoker of thoughts.
I think it would first depend on how French-English relations turn out. There was (is?) the French Separatist movement, which may or may not have occurred in Fallout Universe.
There have been two times when the separatist movements were highly popular. In the 60's and in the mid 90's.
Considering that Fallout diverges from our timeline in the 50's, separatist movements would have died with America's annexation, strong rule and the bombs.
French issued from vaults or who simply survived the Great War wouldn't give a damn about having their french-canadian own territory, or they wouldn't give a damn about fighting with the English Canadians for culture and language. They'd be fighting for resources.
Like in America, canadians, both French and English, would be fighting amongst themselves for resources, regardless of language and culture.