Inside the RV, the air conditioner is hooked up to a 20A circuit from the RV distribution panel. It certainly should be able to run from a 20A circuit.
As others have said, you might not be able to run much if anything else simultaneously. Make sure the fridge is on propane, and preferably have little load on the converter. If the charge line from your tow vehicle is somewhat decent the batteries ought to not be discharged when you arrive (assuming they were fairly well charged when you set out) and so the converter shouldn't be under too much of a load.