looking for help sealing a roof

If the trailer is stationary, you could have a shrinkwrap (like on boats being stored) done on just the top of the trailer, allowing access to doors, windows, vents, etc. A few years ago, I had a guy shrinkwrap my trailer for the winter, and asked that he include vents in the material so that I could use it. I've re-used that cover every winter since. It comes down just far enough to cover the side marker lights. My trailer is almost 20 years old and I became leery of the EPDM roof membrane, which actually still looks good. Dunno if this info is useful or not.