i use conti contacts on my winter bike as well, but my commute tends to not get plowed properly and is not well traveled when i leave for work, so i am going to pick up schwable snow studs and put them on my mountain bike for icey days, days after a snow fall where the roads are chunky and icey, etc

even if i only ride the snow studs a dozen times it'll be worth it, i fell infront of my office 4 times last year

skinny tires are definitely fine for any well traveled road