If you pay $1000/yr to insure a bike, about $850 of that covers you for the Spring/Summer and $150 covers you for Fall/Winter (this is just a hypothetical scenario). Cancelling your policy in the winter will save you very little. As an insurer, your "annual" premium is really a 6MO policy with the off-season months thrown in for free.
So let's say for example, we had nice weather all year round like those middle eastern countries....would our insurance premiums be double because we'd be riding in the months of Oct-Mar?