Originally Posted by The Lev
If the fare is really bad (not normally the case), you can always try flying to BUF and renting a car to get to the YYZ area.
I did that a couple of years ago... my destination was just West of Toronto. YYZ was $1000, BUF just $500. Nice airport too.
I called to make sure I could take the rental into Canada. Hertz said no problem.