There's not much that stops me from getting outside, but freezing rain/ice will.

Running in snow is fun- but you have to go more slowly and watch you don't slip.

Cold isn't a problem either as long as you're careful and wear the right clothes. (Back a couple of years ago when we had real winters, I can remember several early morning cross-country ski excursions at -20 F. You can't stop moving at that temperature, but it's really not bad if you're acclimated and have the right clothes on.)

I have a pair of Stabilicers (sort of like Yak trax but sturdier) that I wear for hiking or walking the dog. I don't think I'd want to run in them though (at least not on the roads- on a trail would probably be fine). I stick to regular running shoes- but again if it's icy (and I can't ski) I take the day off.