It would be easier to visit Homedepot and get a $200 dorm fridge, or bigger and just plug it in. Sounds like you go from house to campground and rarely anything in between.
House fridges are not built for the trailer bouncing, but many do it and are fine.
You might need to run a generator for power on drives longer than a few hours, but still this is cheaper than a new (and soon to fail) propane fridge.
The Danfoss electric fridges really are the best option for many RVers. They use very little power and can run 30 degress off level (propane is 3-6 degrees).
Most of these are "chest" type units, so convert your old fridge space to a closet, and make room for a cooler style chest.
They are expensive.
If you live in CA and the power goes out for the next ten years, then this will run off solar, or a car battery.
There are conversions available to turn your existing propane fridge into a danfoss unit. It will work on some models, but not all.
This would be the ideal solution.