I would strongly disagree, The 2nd half of the Michigan / Butler game will be up against the Buffalo / Montreal hockey game and you will be relegated to some tiny TV in a corner with no sound.
I would suggest trying a hotel bar, specifically someplace which is likely to have a surfeit of Americans, and over-tipping the bartender, or I've had great success watching it online via cbssports.com.
Monday's championship game (go Butler! Go WV!) will be much easier, and viewable in just about any bar with a screen - as there is no 'real' competition from the Habs that night.
I would agree with EaterBob, it is going to be hard to find a place that will let you watch March Madness over the hockey game on Saturday. If I were you, whatever place you decide to go to, you'd better check ahead and see if they will accommodate you in a small corner somewhere. Champs is a pretty good bet according to hubbie. But call and make sure, you don't want to be disappointed.
The other thing is that I like to watch games in bars to enjoy the game in the company of others. It is going to be hard to randomly find a bunch of people watching college basketball on Saturday night in Montreal. If you are looking for a bar because you don't have access at home, then fine. But it won't be a big scene anywhere in this city.
Go Duke! ( hee hee hee!)