5 F today and where I'd normally drive on a day like today, situation demanded I had to bike to go pick up a van, about 10 mi. Coldest commute for me.

Upper body, four layers; lower body, three layers. Snowmobile gloves with liners and wind/waterproof motorcycle two-finger overmitts; insulated boots and thick wool socks. Balaclava + helmet. Pretty much just right. Maybe even one upper body layer too many--probably could have ditched the lined wool vest. And my toes were cold by the end, but nowhere near frozen. Not a bad commute at all, although I don't like having quite so much between my hands and the bars.