If you follow a training plan you should be adjusting throughout your winter cycle training via periodization.
http://www.roadcycling.com/news/article1396.shtml Friels training bible also explains in detail. Can try dead lifts as well, a comnpund movement that will work legs as well as other areas all in one, but be very careful to use excellent form or you can really hurt yourself.
http://www.protraineronline.com/past/nov15/deadlift.cfm