A refrigerator can be placed in an unheated garage if the temperatures stay at 55 degrees Fahrenheit or higher. Refrigerators are designed to be run at room temperature, between 67 and 77 degrees. They work fairly well up to a temperature of 100 degrees and down to about 55 degrees.
When the ambient temperatures get below 50 degrees Fahrenheit, the refrigerator does not run long enough to cool the freezer correctly. The food then starts to thaw in the freezer, ruining food that should be kept at 0 degrees Fahrenheit. When the ambient temperatures are below 30 degrees Fahrenheit, the refrigerator does not run at all.