I'd want to know exactly how much power the AC unit draws. It's on a 20A circuit which provides higher current for starting the compressor but it should draw around 15A when cooling. During the day, the compressor probably runs continuously but at night, it will run part of the time, significantly cutting power usage. If you assume 100% cooling in the daytime and 50% at night, you'll have 18 hours/day of full current draw. This should be around 35kw/day, including power usage for the fan for 6 hours/day when the compressor isn't running. That's around 1050Kwh/month for just the AC.
If it's hot and humid, you might be able to cut the AC usage by setting the thermostat to 80-82F. It'll be warm but not humid inside, a big improvement from outside. Another option, especially for a long term location is to try to get one that has some shade in the afternoon. Anything that shades your RV from the sun will be a big help in keeping it cool.