While I agree that you should take it easy when you start again in the spring, you can still practice certain skills.
As swampduc suggests, bicycling is great training for motorcycling if you are able to do it. It's good for balance, cornering and handling practice, traffic awareness, and for general keeping in shape.
Staying in shape, particularly your ab muscles, will be good to do...remember how important they are for keeping you from leaning too much of your weight onto your arms.
You can drive on your favorite moto routes while thinking about them from a moto perspective, doing so will help you learn the roads better, and you can practice looking through corners and finding visual markers for turning points.
In addition, you can sit with your eyes closed and visualize yourself going through the motions and how you would handle various scenarios. Think about all the different steps involved in making a "simple" corner and go through it slowly, then try thinking through more complex scenarios. It's good mental practice and I find it especially helpful if you are trying to unlearn any bad habits.
Also, if you have access to any moto racing videos, watch them and try to learn from them.
Good luck and I hope your weather warms up soon!
