If you ask anyone in Montreal, there are supposedly "tons" of them. At Mcgill, Richard Raymond, Marina Mdivani, and Kyoko Hashimoto. Not to say that the rest are bad, but I've heard good things about these teachers. At the U of M, of course there's Marc Durand (the head of the dept.), Jean Saulnier, Jimmy Briere, and of course, the winner of the 1980 Chopin Competition, Dang Thai Son. I actually don't know if any of them teach privately; however, since you're already a student of both universities, it might be ok.
Marc Durand is definitely the best alternative, but he is very busy teaching at different schools at the same times, and it's hard to get to him. He taugth to my teacher up to master level, but I think he now only teaches at doctor level.