What you can run depends on your setup and if you have an inverter. About the only thing you can be certain runs on batteries are the lights and trailer brakes. Some propane/electric refrigerators and water heaters have an electric igniter that run off the house battery. The best thing would be to try everything in a 'driveway' test.
If you've got a built in generator, that might run on an electric start from your house batteries. Some generators need adjustments to run at high altitudes, but how high is too high depends on your generator.
2015 Dynamax REV 24TB class C