This is going to be my 3rd winter in a northern climate and as mentioned before its possible to ride. I ride up to anything down to -10C. Warm clothes and studded tires on a cross bike and your off
Most important thing is to keep your head, hands and feet warm. You dont need an amazing-super-dooper 600£ ASSOS jacket (even though I have one), just a lot of the layers.
Im not sure how it is over in Canada but after a big snow storm here the roads a cleared pretty much in the next few hours. Only a blizzard will make the roads un-rideable. Anything bellow that and its ok. Having good lighting is important too of course but more so to be seen then to see.
Only problem with snow and ice is that its harder to do the harder intervals due to the lower friction (unless you have amazing bike skills which I dont). So what I do is long miles outside, harder ones inside on the trainer.
PS: I dont XC ski but a lot of my norwegian friends swear by it and it seems to work as come February they kick my ass big time on the bike. For them Its more like their summer cycling season is to prepare for the winter skiiing and not vice versa
Sunny cycling holidays in Portugal @ Cherry Cottage Vintage B&B