We have never winterized. Luckily we live in an area where we do not often have sustained cold snaps, but they can happen. When we do have a cold snap we put in an electric heater and open all the cupboard doors.
All our plumbing is over the floor boards. We also have enclosed waste tanks and insulated drain valves.
If I was looking at simple overnight freezing or frosts I would not worry at all.
You can easily put a bit of anti freeze in the drains and into the toilet.
Another option would be to leave your RV at a lower elevation where freezing temps are less likely to occur.
