Nice! The worst night I ventured out was -15F with -40F WCF (about 20 mph headwind the entire ride). Made it my 9 mile commute but cold really saps the energy.
Went out at -10F with NO wind and man was that comparatively nice. Made it my entire 25 mile training loop.
No personal experience with studded tires but I think they're mainly for grip on ice. For powder or snow, a knobby MTB tire is probably going to to better because of the deep tread. Generally speaking, though, I avoid all of it and try to stick to roads that have gotten a plow pass. My Schwinn MTB gets good grip up 2" of snow but it's still a better ride if the pavement is closer to bare. If cars have to go around me, so what?
So far my bike has been coated in salt and it does okay, but I'm taking the route of "winter beater" plus nicer bike for rest of the year. Still need to find that nicer bike, mind you. Looking at one tonight!