More info:
1. The trips were actually 3 different RV parks. I don't suspect any sort of electrical issue since I was able to recreate the problem running on electric and gas.
2. The first trip was pushing 100 degrees. There was no recovery overnight when the outdoor temperatures dropped. The 2nd trip was in the low 90's. The refrig temp was around 65 degrees and maybe dropped to 60 overnight. I like the idea of the wireless thermometer though.
3. On other trips, which we were not running the air conditioning, I have been able to accidentally freeze things in the normal refrig section. I really don't think the problem is with the actual refrigerator.
4. Once the refrigerator became useless, there was minimal opening of the door and just to check the temp. We had one of these types of refrigerators in our pop up and are use to the lesser performance than a normal house refrig.
5. It is a Norcold.
6. The AC looks to me as you describe. A "window unit" mounted mostly inside. I think the air intake is from the back of the unit which would be the side of the camper. There is some sort of vent above the AC on the roof. From looking at the AC manual, it looks like the exhaust vents are onthe side of the unit. I assume that is funneled out the top. It is mounted above the refrigerator. Inside the camper, there is a countertop mounted on top of the refrigerator, then about 6 inches of space, then the AC unit which uses the rest of the space up to the ceiling.
7. The refer does have 2 sidewall vents. The 1st trip when this failed (2 weeks; 1000 miles from home), I called the service technician. He suggested purchasing a small desk fan and mounting it in that space, blowing air up across the fins. It maybe made a 2 degree difference.
8. I was level. That should have been the first question. . .or the first item I mentioned.
