[Arkware]

It sounds like your dealer supplied batteries were undersized to begin with.
So, only 80 AH seems to be underpowered, too for your Residential Fridge.

I went with 4 - 6 volt GC batteries that are rated for a total of 440 AH.
Even with about half safe usage, that still leaves around 220 AH.

I believe this will give me plenty of travel time with power left over if we are delayed and need to stop overnight...

Your mileage may vary....