YQB is a one terminal airport. I'm trying to remember if you can go from the domestic to the international side, if not you can always just hang out at the (pre-security) Tim Horton's upstairs. Pretty easy to use.

Not sure about the luggage as I usually seem to fly out early in the AM, but there again, worst-case scenario is that you hang out with your luggage at Tim's - it's got a great view of the runway at least.