Up here the few bike lanes that are around are covered (sounds like everyone's are). MUPs are for the most part unplowed. Once the powder gets about an inch below my 26" hub it's unrideable. To their credit the actual city will clear the portion that falls within the city limits a few days after a good snowfall. Unfortunately, this is almost useless for transport since "the city" isn't that big. They also use a snowblower vice a plow which leaves nasty ped/animal ruts, and an uneven surface (and then there's those icy bike tracks, who keeps leaving those? haha). It's pretty hazardous once it freezes as it's like riding over the rails over and over again. I don't hold it against them, the whole area is short on funds.

The trail advocacy group keeps the section north of the city groomed for x-c skiers. I keep off of this out of courtesy to them.

In the winter I just take the lane, and keep one eye on the mirror in case I have to ditch for the plow/ errant motorist.