RP wrote:

So subfreezing condenser air might hurt the compressor, and controlling
the fan duty cycle to keep the hot coil above freezing might avoid that?

It might, that is, if you could insulate the coil from the ambient
environment during the off cycle.

With little mass and no fan, it might heat up fast...

At 100 W, 10 Btu/F would warm 35 F in 1 hour, so maybe we need insulation
and/or heat...

You have to count the compressor mass, and take into account that the
cycle will be extremely short given the low load condition due to
subfreezing ambient around the box.

Less energy use sounds good to me :-)

Here's my suggestion: turn it off, take the food with you Somebody is
likely to break in and eat it anyway while the cabin is unoccupied for
long periods.

My poor friend just wants to keep ice cream in her full-time 50 F house,
not to become homeless :-) When I kept my old stone kitchen at 36 F,
the fridge seldom ran but the frozen food tended to thaw. OTOH, leaving
the carton of milk out on the counter overnight wasn't a problem.

Refrigerators take awhile to stabilize running pressures, so starting with
a subfreezing condenser coil might mean that the cycle finishes before the
head control even has a chance to takes control...

Is that bad, or just a transient self-correcting condition?

Nick