Other tips for surviving in high heat regards the fridge:
Try to shade the fridge side of the camper as much as possible. Turn the camper, if possible to put it on the "shady" side of the sun arc. Keep the awning at least partially out if it shades your fridge location.
Add 12 volt booster (computer) fans inside the exterior of the fridge vent to boost circulation (and thus cooling). They make a replacement top cap with solar powered fans https://www.amazon.com/Camco-42165-R.../dp/B0012FEX5K
(but to be fair I have not heard that much "long term" good reviews due to the solar panels being plastic and they opaque from acid rain and such.
If you are handy, but don't want to modify your camper, it would be fairly easy to make a multi-fan (4 or 6 fans) on a sheet of ridged plastic that you hang on your lower fridge vent when you need it so it can be removed when you don't. A 12 volt power wire can be fed through an existing hole in the vent. Obviously, the fans should be hung so as to blow air INTO the camper's lower vent.
You could also put a small switch on it to shut the fans off at night so they won't bother you when you sleep.
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