This is a good time of year for biking. It’s cold but you can dress for it and there’s not yet snow on the roads.
The first year that I biked full-time I tried to bike through the entire winter. The paths aren’t cleared of snow so I was on the side of the road. It was plowed only because the road was plowed for the cars but there were bits of slush that piled up at the edge.
It wasn’t so much the difficulty of biking through the snow (though that can be a lot of effort), it’s that the slush would freeze, and then fresh snow would collect on top. The front tire would get caught in the grooves and suddenly I would be pulled in a direction that I wasn’t heading and I would fall off the bike.
I’m not an adventure-seeker so I decided I didn’t have anything to prove and I started taking the bus when the roads became too messy.