hey man i was in your same position last year
i guess il start off by giving you my 2 cents on your three choices
1. McGill is an unreal school all together. Location is prime (skiing, partying, girls, etc.) so you dont have to worry about that at all. They have great spirit, from the people i know that go there, they love it. Business there is pretty dam good, good rep too. Solid choice
2. The one big thing about western is getting INTO Ivey. Alot of people go to western to go for business. You dont apply for Ivey until third year i believe and you'll be competing against ALOT of kids. One of the reasons i didnt pick it is because i wanted to make sure i was in the program i wanted to be in and not have a chance to not make it. I think Western puts out a few offers on advance entry into Ivey so if you got that, good for you. Ivey itself is an unreal program, nothing else to say.
The school itself is pretty awesome. London is a super fun town to party in, not much skiing though. When people say Western is a party school, they really mean it. If you decide to go there, i can guarantee that your party life first year will exceed your expectations. Seriously that place can be crazy sometimes. Ive gone there for 1 weekend so far and plan to go for more, just for the party life ;)
3. Cant really say anything about U of T except it being a top school. I dont know anything about the International Relations Programs but Rott Business there is top notch
Some schools you might want to look at besides your 3 are:
Concordia: Good business school, again in quebec. great city and skiing
Mcmaster: again good business school. Its in the Greater Toronto Area. Decent skiing, great school and people. Guarenteed good choice (bias cause i go here)
Laurier: Top notch business program if you get in. close to Mcmaster and pretty much in the GTA
Why dont you go to Simon Frasier (?) or UBC. Great schools and great skiing.
If you have any questions about schools in ontario, pm me or post in ontario forum, lots of uni kids will reply
Just curious what the competitive averages for general arts are out west? UVIC, UBC OR U of C