I don't run outside if the footing is really bad. It's too easy to hurt yourself, not just by falling down but also due to the stability issues Grog mentioned. Running on ice is a good way to get an overuse injury like a tendonitis because your muscles and tendons have to work harder to stabilize you.

But if you want to run in that weather, most running specific stores now carry the stabilizers mentioned above.

As for running in the super cold, I am also from Alberta and I have been known to run in that knd of weather in my youth. However, when I took sports medicine at University I learned that most running shoes lose all of their cushioning properties at below -20 C. So that became my cutoff.

No need to ask for an injury IMO.