I bought a refrigerator cheaply second-hand, but it turned out to be a freezer. On the lowest setting, it goes down to -14°C. And I think I found a great solution to convert it from a freezer to a fridge without replacing the thermostat or buying another one. I purchased a $11 box on Amazon that plugs into an outlet and switches on and off programmatically. It has many modes, one of them is — work N minutes, rest M minutes. It comfortably handles the power load. Right now, it turns on every hour for 10 minutes. And so far, with these settings, it maintains a steady +4 °C all day long — just what you need for a refrigerator (Inside the refrigerator, I have a radio thermometer from a weather station to monitor the temperature).
Hi, I'm Rauf Aliev. 