I'm not biking this winter as my winter bike from last year has been absconded by my son. However, last year, I rode a few days in -29C weather (wind chill -39C/-38F). Regular mitts with a wool liner, helmet/balaclava/ski goggles, snowboarding pants/thermal undies, snowboarding jacket/thermal undershirt/scarf, hiking boots/mid-weight wool socks. I was fine, just dress for it.
This winter, I've been walking in as much as I can (~4km/~2.5mi, 45-50min) and the last couple of days have been cold with -34–36C (-30–34F) temperatures and wind chills in the -42–44C ranges. Next week is forecast to be 10–15 degrees milder.