Winter came late this year, but now it's hear. And it has come in hard. Early snow & super cold temps.
I decided to ride my single speed Salsa el Mariachi for my cold & snowy commuter this winter, outfitted with 29 x 2.1 Nokian Extreme studded tires and fenders. The 45NRTH Cobrafist pogies are total game changers. I was riding yesterday at -18 degrees and my hands stayed nice & warm with only light mittens.
I'll ride my 10yr old Jamis Coda on days w/ clearer pavement and warmer temps. I still have studs to deal with the occasional icy patch, but the thinner tires are all I need when there isn't much loose snow to deal with. I added a Surly Singleator a few years ago after the old derailleur pretty much rusted off. It's a perfect bike for riding on dirty winter roads - completely vulnerable to corrosion, but that's why we have dedicated winter bikes.