Does an absorption refrigerator need winterizing

Since an ammonia based fridge has water in the system, does it need some form of winterization? Our camper will spend its first winter in really cold temps. Northern Idaho can get down to minus 35. It’s always wintered in Texas before, so the question has never arisen. If it needs some protection the only thing I could think of is to leave it plugged in on a setting that will cause it to run periodically since you can’t get into the system. I am assuming nothing is required, or I’d be hearing of more problems with these types of fridges. So the ammonia must act as an antifreeze. Am I correct? I don’t want a bad fridge come spring.