My RV is 30 amp--however I added two additional shore power cords. I use plugs so I can run the converter separately--then run the RV off the inverter. I use plugs on the water heater, too. The same could be done for a 2nd air conditioner.
This gets around the gfci problem.
This modification allows me a continuous load of 5400 watts, with a peak load of 7300 watts. That, in turn, allows me to heat 100% electrically at -37 c (-34 f).
It's great for places where there are multiple 15 amp outlets on separate
breakers. Combining it with a hybrid load support inverter/charger means I can run lots of items.