I did a lot of reading about the marginal power at campgrounds and decided I didn’t want to take a chance damaging the air conditioner, refrigerator, etc. So I installed the "Progressive" hardwired version power protector, EMS-HW30C, and mounted the remote display panel above the thermostat. Two times already it has cut off the power to the trailer when the voltage has dropped below 104 volts, very happy with the performance. What's nice is when voltage is restored to an acceptable level it turns the power back on automatically.
What’s funny is the two low voltage occasions that I had were at state parks, not private campgrounds. That’s when I decided to buy the Hughes Autoformer RV2130, quite a nice little product. I actually got to talk to the company owner at an RV show. His demonstration of the unit made the decision a no brainer. After using this I have noticed, via the “Progressive display panel”, that the voltage is always at an acceptable level now and no more low voltage alarms.
A lot of protection over kill, maybe, but both items wouldn’t have cost what a refrigerator would be to replace.