OP I have a question for you are you actually asking about CANCELLING your policy or just going to fire/theft/comprehensive for the winter?
They are VERY different things.
If you cancel, you WILL get hit with cancellation fees, This is to discourage people from doing exactly what you want to do. Decades agao you could buy a policy in May and cancel in Oct with no penalties and no paying over the winter. Not permitted anymore, (actually is permitted you just have to pay the high fees to do so. Also after you do it twice they will see the pattern good luck finding an insurer then.
Next so you cancel outright. Are you 100% your bike won't get stolen when you have no insurance? Or that a fire, (if your in a house your neighbors garage goes up and ignites your garage, or in a condo the neighbors car catches fire and before the sprinklers go off your bike gets singed. unless it is a piece of crap that is worth say $500 your SOL. In which case cancel away...lol