IF you have a 30A trailer, watch the AMPs on the heater(s). It won't take long to trip a circuit breaker as most of the outlets are on one circuit.
IF you have a 50A MH, watch the AMPs on the heater(s). Most likely your outlets are powered THROUGH your converter/interver and is usually less than the 50A (e.g. 30A or 45A, depending on the size of the converter). You might be able to find an outlet not running "though" the converter. Disconnect the shore cord, Genny Off, Inverter ON. Use a 110v item to identify which outlets run "through" the inverter even when the inverter is OFF.