Winter is a hard time to to stay motivated to train. Your season is over and the next season is still a long way off. A good way to stay motivated is to find active things to do with friends and family. Take a TRX class together... or yoga or pilates etc. If it's not too cold where you are find something active to do outside with others. Maybe join a masters swim group to help motivate you to get in the pool during those cold winter months. Sign up for a race. Having that financial commitment will help motivate you and remind you that you are committed to something. Vary your workouts so you don't get bored. Put stickies on your bathroom mirror with reminders of a race you've signed up for and goals you have.
Enjoy the offseason!