I'm not crazy, the attack has begun.
You are both potentially right. Some cars limit AC operation according to external temp to avoid freezing damage to the evaporator, that is dead right.If you say so.
Didn't work on most of mine and the handbook stated it wouldn't below 5C. (C5, CRZ, Guilietta, Brera etc)
Instead I let the engine warm up so hot air did the job.
My 14 year old van has an ice detection on the matrix itself to stop it getting that cold, as many cars do. Doesn't even have an external temperature sensor!
Not operating the AC below 5C external is the 'cheap' way, not essential way, but all cars should have some way to avoid frost swelling in the fins of the evaporator (cooling) matrix else it risks destroying it.
I don't think some of my old American cars had anything like that, in fact on one of them there was actually a button 'defrost' that activated both the AC and max heat. I suspect more hardy designs of evaporator matrix back then. It was a 1976 Plymouth with an AC system little changed since it was originally designed in the early 50's. I would guess wider fin/channel separation to tolerate that sort of thing.