You'll have to determine if there is space in a wall to run the duct. Usually RV walls are pretty compact, being a sandwich of outside surface, insulation, then inside wall with little space. If you did move the duct to an outside wall, I'm afraid you'd have to do it at the expense of the insulation.
Moving the ducts to cabinet bases, inside walls, or dinette bases might be possible, if they aren't already being used for wire chases or for appliances or systems.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI