I think its good to have one good heavy guage (12 or 14g) extension cord for this sort of use. In theory two refrigerators could trip a 15A breaker with simultaneous motor starts, but I've never seen that happen in practice.
My refrigerator maxes out at about a 3.5amp draw. A lot of the modern ones run at a lower wattage for a longer period of time. The older ones can draw more for a shorter period of time.
Genius
It has one major, major downside, which is recurring visits to a ford dealership.
not in my case. ymmv.
going to the dealer for routine service is an example of recurring visits. And going to dealerships suuucks.
"...maxes out at...3.5amp"
While true, it varies heavily by refrigerator brand and type. I have mine closely tracked on a home energy monitor. Surge current caps out at 500W for roughly a second, and might run at a peak of 373W for about 10 minutes. Most of the time it hums along at about 130W. This is a decent example of a more modern refrigerator. I'd be comfortable putting two of these on a 15amp circuit in an emergency backup situation.
Yes, it does vary widely. I do work on small refrigerated lab equipment (cryostats, incubators, refrigerators, freezers, cold plates, etc.). I have often used a Fluke peak reading TRMS meter with a current clamp on these, to observe peak currents at start up. While the peak surge currents on your refrigerators may indeed be much lower than what I see on the equipment on which I work, I suspect that the actual currents are much higher than what your home energy monitor is telling you (it is probably giving you an average over a short period of time, perhaps a second, but not a true peak). The physics is still the same, though - use the shortest and largest extension cord you can - not because the stable running current is exceeds the rating of the smaller/longer cord, but because the surge currents on compressors can be very high. This will help keep the surge peak short. Note that this can increase as the device ages. What was fine when it was only one year old may not be fine when it is five years old - it may take more current to overcome worn bearings, etc. Check the locked rotor current rating (LRA) on the compressor, in order to understand what the maximum of the device is.
