What kind of insurance coverage does everyone have?

Living in Minnesota my vehicles are parked for several months out of the year. I was wondering what kind of insurance coverage everyone has on their collector vehicles and what it covers during storage months? I need to get coverage on my duster and my 67 D200 but I want to make sure they are covered incase of a fire or a roof colapsing because of heavy snow. I have talked to my insurance agent and there is custom insurance that you can set the value of your car or there is collector insurance. The problem with collector insurance is you can only drive it on a limited basis. Does anyone have custom insurance and have you had any issues with claims if God forbid an accident would happen?