Canadian here, living in Montreal. While light pollution is always a problem in any city, dark skies are only 90 minutes away north of the city. I was at Lac Memphremagog this summer and while I had bad luck with the state of the sky, it was obvious that the area is quite dark. No large towns nearby and sparsely populated. The view I had was to the north, so no light dome, and when I got a break from the haze the view was incredible. I imagine if my view was to the south, the light dome of the Montreal-Laval area would be in evidence, but still pretty good. I was also in the Laurentians later in the summer and again, very dark sky since we were away from the ski towns.
Winter though - not at all ideal for observing! I actually started observing in the winter, and my temperature limit was -12 C (5 F). Anything colder than that was excruciating. Actually, not much fun at -12 C either but when I've gone two weeks without observing, I'll put up with the cold.
So, the advantages - not too far from dark skies. This probably wouldn't be the case in the Toronto area - which is among the most densely populated areas in North America. The disadvantages? Quite a few. While we have long nights in winter, they tend to be cloudier and very cold. Summers tend to be very pleasant and clearer, but the observing window is very short. Around the solstice here in Montreal, the most time I can hope for is about 4 hours, from 22:30-2:30.
Good luck to you!
Edit: I realize now that I didn't really answer your question. If the cold frightens you, then go to British Columbia but if you can stay away from Vancouver. It's very expensive and even cloudier in winter than Montreal. If you think you can handle the cold, then maybe Bishop's University in Sherbrooke, QC? It's also relatively close to the Lac Megantic observatory and in a beautiful part of Quebec. Sherbrooke is a small city of 150,000, but the surrounding area is sparsely populated and you wouldn't have to travel far for a dark sky. Also, you'd probably be OK doing astrophotography within the city itself.
Edited by jpcampbell, 28 October 2019 - 09:51 AM.