I started commuting thinking to myself I'd ride every day unless there was 6+ inches of snow. Packed snow is no problem, water is no problem. It's the ice and to some extent the cold. 9 miles is too far to go on ice, it just takes too long and it's not worth falling. I don't have/need studs since the ice conditions maybe occur 10 times in a season. On the cold, I have pretty much set a 10F degree limit. Below that and/or ice, I ride the bus.