I had a similar problem with only one 15,000 BTU on a Holiday Rambler 30 footer. I resolved the problem buy installing a second AC unit in the bedroom and installed it to the ducked air. My rv came with a pre wired bedroom wiring for a second unit. the installation of the 10,000 btu unit and labor cost me less than $2,000 the bedroom unit works independent from the front unit.You can run both units when connected to Shore power. The geny would not run both units simultaneous but will run either one of them, by selecting either via selector switch. If interested i have additional info on the installation