Not personally. Depending how far north you want to go, I know they are some native communities and outfitters in that area.Are you familiar with the North Road that connects to the James Bay Road? I'll be taking a trip up there in a few weeks? Seems very remote.
I've done some research on OverlandQuebec and it's looks like some large portions of roads are asphalt (like between Matagamie and Radisson).
Some pictures I found (in French):
2010 james bay teritory tour !!! - Autres loisirs - Overland Québec
A la recherche du Nord ! - Page 3 - Complètes - Overland Québec
Beside visiting the dams near Radisson, I don't think there's much to do there. You can also try to go to Caniapiscau also.
Post in that section on OQ and more knowledgeable people will be able to answer your questions!