sparrks
One thing I would avoid is a compressor fridge - we had one & it absolutely sucked the life out of the batteries. Could never get enough air flow around it, even though we put an outside grid at the back of it. We may have been unlucky, but it was an very expensive white lump, especially when we travelled in Europe & it was warmer than here. We did our best to avoid using the invertor as well for the same reason.
Sounds like you were unlucky, mine draws about 4A whilst the compressor is running which runs for about 15-20mins an hour. That works out between 1-1.3Ah or up to 32Ah per day. I chose a compressor fridge as I do not have a fixed gas supply and use a small but very efficient camping stove. With a couple of 100w solar panels the draw on the batteries would be small, especially travelling around Europe as you were.
As for air flow never been a problem, certainly no grids to the outside!