OK, here is what I do and it works for us.
I set the temperature on the thermostat to be 10 degrees lower than the outside air temperature. NEVER lower than 68.
This allows the unit to cycle, prevents coil freeze up, and keeps the camper comfortable. You won't be wearing a sweater inside, but 10 degrees feels great when you go inside.
Cycling is critical for water removal and proper cooling. If the coils are too cold the air flow will begin to drop and water that would have been deposited in the drip pan becomes frost on the coils. As frost gets thicker, air flow drops even more and the unit will eventually ice up, run constantly, and stop cooling.
When outside air is above 100, I set the air conditioner at 90 and take what I get.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW