That is really interesting --- I have boondocked several times for a weekend trip with my CF35 (CFF35 has the same "guts") and a battery lasted me from Friday night until Sunday mid-day, both in my 2021 as well as my 2012. With a 200 watt solar panel, I suspect I'd have a full battery by mid-afternoon or earlier if there is sun. Worst case, I do have a honda 2200.
The airflow around the fridge is important. The CFF35 seems a lot more sensitive to that than my CF35 was. We traveled with the CF35 in the galley across the country and it never was that bad. The CFF35 though --- it definitely is pickier.
But, If a yeti or similar can keep ice blocks for a couple days, this might not be a bad solution. I need a way to move meat around safely. Usually quite a bit of it. We eat mostly carnivore when camping, and meat above 40 degrees -- yah, not a good combination. I have been told the Yeti and knockoffs handle this pretty well.
I had a Coleman cooler, but it died a horrible death. It never worked that well for us -- the lid was too loose. For a beer and ice chest, the coleman was great. But I have doubts for meat, and suspect the rubber straps would be far more reliable.