SLIDE WARNING:
Thanks. We only have about 2-3 months of intense heat. And winter is up and down.
I think in a long term down we’d just do without the refrigerator, and make sure there were no leftovers.
I have kept milk over night by throwing wet towels all over the jar-works pretty good.
A well built 'root cellar' should maintain a constant temperature year round. That temp will vary some with location, but in general 55° - 60°. That greatly simplified controlling the variables. A hundred years ago people stored milk submerged in mountain streams. Very reliable constant. But burying (root cellar) below ground surface temp level is the most reliable. Also refrigeration is easier - although running the cooling compressor yields heat exhaust so that may need to be vented.