Breaking away from Canada would be stupid. It wouldn't survive economically, politically or militarily.
Militarily? Who would invade La République Québecoise?
Politically? I fail to see that. Granted, the PQ would likely fracture into multiple parties once the goal of independence was achieved, but the death of a political party is not the same the death of a country.
Economially? Unless Quebec refused to remain part of NAFTA, there is nothing as far as extermal ecominics that would be a problem, as I can see any of the NAFTA countries refusing her admittance unless Canada decides to be petty about it, but if Canada was, there certainly would be a bilateral US Quebec Free Trade Agreement that Quebec could accept I'll admit that I don't know enough about internal Canadian economics to judge whether Quebec is subsidized by the national government or not. But with the probable breakup of the PQ, the econic policy of an independent Quebec would be next to impossible to predict.
Canada would be the real loser if Quebec were to succeed, because I fail to see how Canada would be able to stay united once Quebec left.