It obviously depends on the type of insurance that you want, basic liability, full coverage, etc.

Some insurance companies let you suspend a policy when the car isn't being driven.
State Farm limits that to 6 months tops of suspension (winter, etc) and after that you either have to reinstate it or cancel it..
I know guys that do that, they only put the insurance on it when they make plans to drive it.

You can also drop it down it just comprehensive (if you have full coverage) that way it's covered by acts of god while in storage.