It was common in the US up to the 1960's. My dad was a conductor and one of his jobs was to lock the restroom doors just before the train rolled into a station.
This. I live up in the Sierra Nevada mountains and have had two winters where the power was out more than a week. I do have a whole house generator, but it's runtime has to be rationed to save propane.
Mini-split heat pump heat and cooling, AFAIK was not an American invention. It was widely adopted in Asia and lesser so in Europe. USA lagged behind but is catching up now. The ability to only heat/cool one or two zones with a quiet and efficient heat pump is far better than central air conditioning/heat.