I dont know how much you unpack but I have a plastic storage bin that I put all liquids in ie; shampoo, liquid hand soap, spray cleaner, laundry detergent, bug spray, dish detergent, tank chemicals. and take them home so they dont freeze. I also bought 6 large vacuum storage bags at the dollar store and put the clean towels, sheets, blankets and pillows in and use a small vacuum to shrink them down and store them in cabinets just to keep the mice from chewing or making a home in them. I always put some RV antifreeze in the drains. If you drain them completely the gas from the holding tanks can come back up through and in a closed RV
. I open the low drain points and put a few gallons of bleach water in the fresh water tank. You dont need much bleach, just a few drops per gallon and just enough to slosh around the bottom. Since you can not get into the tank to clean it you dont want anything to start growing in there. You may be able to kill it later with a shock treatment but you can not scrub it out. The mild chlorine off gas will stop almost anything from getting started.