I do it a lot in my 50a RV, and i have an adapter that lets me connect into 2 separate 15a circuits in the house. I monitor voltage, and use 12ga extension cords.
My EMS gives me clues about what works off of each side of the 2x50a system so I am careful about what AC can be used. Initially, the battery charger and refrig use up enough that one AC can not be used, but the other is sitting on an otherwise idle load circuit. When I notice the battery charger is at a near rest, I can run both AC units.
Besides voltage, the risk is a tripped circuit breaker in the house, low risk. People get close to that every day using a hair dryer on high.
The attention and care are about the same as I have to employ while camping on a 30a site in the summer. One AC at a time, unless everything else is idle, then 2 can be used. Never combine microwave, coffee maker, etc. and AC on the same side.
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