The ac will freeze up if you go a lot lower that out side. 15 to 20 degrees is a guess. We did freeze ours and a new GMC when it was 105 in Atlanta and the car was set to 60 degrees. We have replaced our 15000 ac in our alpenlite 2 winters ago.
What brand did you go with
At 96 degree in full sunlight I couldn't get below 85 deg inside I am going to check the intake and exhaust numbers next time. I didn't have my infrared temp gun with but I am thinking we are going to add another unit in place of the fantastic fan in the bedroom.
I am assuming it is wired and ducted in the bedroom if so any suggestions on who as the best low profile ac unit.