I'm from Montreal.
You'll find most of the hotels in downtown, staying on University St is a good idea as you'll be close to the public transport if your not renting a car. The stadium where the tournament is played isn't in downtown however, it's a bit more to the north. If you plan to rent a car, I would suggest renting an hotel close to the airport as it will be easier for you to travel from the west side of Montreal to the area where the tournament is held by car, however expect to shell out 15-20$ for parking at the stadium and parking at the hotel probably won't be free either.