> The trick is to avoid sweating.

would I would imagine that you might want to avoid any - ice + snow patches as well, don't know if you can get * tires for bikes.

I used to bicycle commute to work in Ottawa year round (I'm not smarter now, but I work from home instead) and as you say, it's totally feasible (fun even!) as long as you dress smartly and ride at a fairly casual pace. If your bike breaks down you're definitely better off walking it somewhere warm to make repairs rather than fixing it on the side of the road!