Where do you store your camper? How cold does it get where you are at? Do you have a lead acid battery or lithium?
On many of the newer campers Jayco's BmPro/JayCommand along with the CO/gas detector bypass the battery disconnect, which will drain a battery in a few weeks. Personally, I would physically disconnect the battery. If your in a really cold location, pull the battery and keep it in a warm environment (mostly above freezing). A charged battery will not freeze.
If the camper is at home and can be plugged in, leave the battery in the camper let the on board converter keep it charged all winter. If you have a maintenance lead acid battery (most common), make sure the fluid levels are topped off, ONLY USE Distilled water.
I pull my battery, and put it in my shop. I'll put it on the trickle charger maybe twice during the winter. The voltage may drop 0.1 volts over the course of the winter.
As for the tablet, I suspect the best thing you can do is pull it and charge it in the house over the winter. Lots of people seem to have dead battery issues with these tablets in the spring.
2012 Jayco X23B
2020 Ram Laramie 3500 SRW Air ride 50Gal fuel tank.
2007 Dodge Dakota Quad Cab (retired from towing)
Equal-I-zer 4-Point Sway Control