When it gets real cold (30 or below) I tend to stick to just riding back and forth to work (20 minutes each way). Longer rides are a little too painful (aka not as much fun). I have cold weather gear but I (as yet) don't have any additional heating (grips, vest, etc).
I ride all year except when the roads are unsafe (too much salt/sand/snow).
I ride all year except when the roads are unsafe (too much salt/sand/snow).