There are many areas in a TT that get closed off by the manufacturer that can be opened up for storage. Sounds like your idea would work. You can always put the paneling back if it doesn't work.
Most trailers I've had have had panels in various areas like under the bathroom sink that were stapled in. I've opened those up and have gained huge storage areas. I buy those little gold hinges and magnet closers so they can be opened and closed. Then drill a 3/4" hole in the door to open it, don't need knobs that way.