I commute to work by bike all year round, only half an hour each way, don't really have a problem with my upper half getting cold, it's more my lower half. My heated seat does help on that front though, warming up the blood travelling down that area.
This must be one of the best bikes to use in Winter, not that I see many other bikes on my commute during this time of year but I would hate to be on a naked bike for example, heated clothing would be a must have then I think.