There really is not much more to the plumbing winterizing than the pink antifreeze. I would remind you to open each and every value that deals with water. Its important to make sure the antifreeze touches everything.
Lets talk mice! You need a plan to keep those friendly little critters out of your camper. Everybody has a different method to handle this problem. I can only speak about mine do not know is right or wrong but for me it works. If you have access to keep unit plugged in. I use the Bell and Howell mice plug in sound things from one of the big box store. Mine are plugged in all the time. I also use an large quantity of moth balls, 2 boxes. I will pour some moth balls in small plastic cups and put in drawers, under bed, out in open, I even put in outside bays. Knock on wood not mice problems for many years.
Good Luck