I'm not too familiar with the GTA, but from Google Maps it seems like a commute into downtown Toronto takes about an hour via public transit. Do you plan to live in graduate housing or to live somewhere between downtown and the campus itself? Having lived in big cities where commutes are just a part of daily life, I am not necessarily opposed to the possibility of living off campus, but there are many nights when a 5 minute walk back to the comfort of your own place sure beats a 40 minute bus ride!