We tend to get quite a bit of snow in Canada, and it is pretty cold. I'm not sure if riding in the winter is common elsewhere but where I live in Canada I don't ever see cyclists in the winter.
I live in Boston, and while it isn't Canada, it can get quite cold in the winter. Plenty of people here, I included, bike in the winter. As long as you wear the right clothes have low-temperature lubricants and winter tires on your bike, winter biking isn't that big of an issue. If anything it's better than summer biking because I don't get as hot or sweat as much. Mud season is far worse for biking, but it last only a month or so if that.