Can't believe we are talking about winter already, it feels like summer just started.

I usually ride outside on the weekends until about mid-Nov and start up again in March. During the week I do spin classes 3x per week from about Oct-Mar.
Mostly because I don't have enough non-working daylight to ride.

I swim year round as well as run outside year round. In the winter on the weekends we x-c ski and hike.

I usually find that by doing the spinning classes and keeping active all winter I haven't really lost any fitness when I get back on the bike in the spring.