Using fridge in feezing temps

X2 on what GordonThree said. Ours froze one winter in Carson City, we had to replace the cooling unit. What a pain

I lived 2 winters in my TT in Alberta.

In the minus 20's for weeks on end the refer was ok.

Had a few issues when it got to about minus 33 C. I had to block the bottom air intake and put a 100W light bulb in the back to warm up the back of the fridge to keep it running.
Also had to put a heating pad in with my propane bottles to keep enough flow to run stuff, especially the furnace.

At a few degrees below freezing your fridge is absolutely a non issue. Don't even think or worry about it.

A few nights Dec16 / Jan17 at -36. Dometic model 3962? - trailer connected to shore power at the time. Fridge kep on working normally.

Continuous living in those temps I would maybe find a porous non combustible material to pad the vent door to reduce the direct icy blast of air during an OMG Polar Vortex Event / Warning / Advisory.

Had to put a little electric cube heater by the propane cylinders and throw an old blankie over them to keep the propane boiling.

We've never had issues camping in cold weather with our Norcold. That said, once the temps get to the teens, we stay home as that's pretty much where the RV stops being comfortable inside. While the furnace will keep the temp OK, you can just feel the cold near the walls and windows and it starts being a real chore to keep the water/sewer working right. If we're not comfortable, camping stops being fun!

I've camped down to 12 degrees at night with highs below freezin with no ill effects on my RV fridge. Maintains the temp it was set for and works fine.

How far below freezing?

30s overnight no probs

Consistent 20s at night and 30s during the day it's time to block vents and install a light bulb near the back of the unit