We look at our 5er as a stand alone house. It has its own clothes, phone chargers, cords, movies, kitchen accessories and food. The only food we take out when it isn't winterized is the milk, some meat, and eggs. When we winterize, we leave anything that won't get hurt freezing. We leave our fridge on all summer once we start it, so that food stays also. If you can't leave your trailer plugged in, just take a cooler to carry that stuff.
Make it as easy on yourself as possible. We live in forest fire country, so we can hook up and leave if necessary. It is a nice feeling knowing that if something happened to our house, we can still live a normal life. A little off topic, but if you do this, there is minimal loading and unloading to be done.