Much of that depends on the outside weather. My son gets a big kick in the movie 'Ice Station Zebra' where the rescue team rushes in to the crew quarters during a vicious polar storm and to the right of the entrance there is a refrigerator!
A freezer here in Florida during hurricane season, inside out of the sun, would probably need to be run an hour twice a day for four days. Then longer and more frequently. A refrigerator here with milk and dairy within would probably need at least two hours twice a day for three days, then more often. In a milder climate one might get by with less running time but not really much less.
What one is cooling can make a difference. The Pfizer CoViD vaccine must be stored, I believe, at -70° constantly. It is stored in dry ice. Any thawing probably means discarding. OTOH, ice cream here in Fla could stand some mild defrost in summer and still be refrozen quite safely.
These are impressions and limited experience in a sub tropical setting. Common sense and detail of circumstance pose solutions. In the four 2004 hurricanes here a great effort was made to truck in huge quantities of bagged ice. The last few seasons no real effort was made. So many variables.
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.
You’d think block ice would be more helpful than bagged.