As experimented both Montreal and Québec city
Hi there.
Just wanted to share my experiences here and, as far as I know, there is quite some polyamorous guy-into-guys in Montreal. If your are into online dating, I recommend OkCupid. There is quite a lot of active Montreal profiles.
In the span of a few (5) month living there, I've meet 2 polyamorous guys. One with a girlfriend that we told each other beforehand that we were polyamorous and another whom we meet firstly for just casual sex. In fact, I am currently dating that guy in Montreal and when I came out to him that I had feelings and I was interested in multiple loving relationship, he told me that he shared my feelings and identified as poly too. Just keep looking, you will eventually find that missing piece. Remember to stay flexible, as it is pretty much the philosophy of living a polyamorous life.
However, I have been dating a lot in Québec city and so far I have yet to find anyone interested in that kind of relationship. Oh well. Maybe it's just luck or the plain fact that there is less polyamorous people in Québec city. It is smaller then Montréal after all.