Yeah, "Hook" used to ride his old 40's something bike he had outfitted with skis from an old snowmachine to his rear axel all Winter. Had a big wool blanket fashioned into an engine cover and wore full up military extreme cold parka top and bottoms.
I've heard, but haven't witnessed, that some of the folks in Anchorage still ride their 3-Wheelers with studded tires down there, but then they don't get the extreme cold temps up here in the Fairbanks area.
I'm a die-hard rider... but a Man's got to know his Limitations. I prefer anything above + 40 with clear roads... there may be snow on the shoulders and in the ditches, but the pavements are kept clean by all the cars and trucks. Ice on the road is my cuttoff, but I've been known to ride that stuff too. Lucky I guess.