Unless I missed something, isn't the party and the camping separate events? If you are uncomfortable taking out the trailer and staying in it for the weekend, stay home and drive your car to the party. If you lose some money because of deposits at the campground, so what? They didn't cause the weather to be bad and they met their obligation of having a site for you. If you are so tightly wound that you have become so inflexible you cannot change your plans due to something you cannot control (the weather), you really need to go to the party and loosen up.
