Winter Dry Camping Tips

We are taking our 21FBS on our first winter trip (first dry trip too!) in Julian, California for Thansgiving. Two questions:

1. Our water tank is empty. Any suggestions for purifying the tank?
2. The temps will probably drop below freezing and we might have snow. I understand that our tanks are insulated, but is there any thing else we need to do? I'm thinking of the water hose, etc.

Thanks in advance!

Steve and Sharon, i recently spent our bow and arrow season in the hills. and most temps at night got to around 22 degrees i kept water in the trailer until rifle season and the temps went to around 15 at night and days are now in the 30"s. then i winterized it. so i think as long as your temps at night are around 25 plus at night and your day temp rises , your tanks and lines maybe ok.

Add an ounce or two bleach then fill flush it a few times will prepare the tank for use, we don't drink the tank water so no prep is need normally.
Fill your water tank with a hose during the day and disconnect it at night from the hose bib.
Using your propane ducted furnace will keep the fresh water tank from freezing.
We have stayed and enjoyed a Thanksgiving or two near Julian/Butterfield country before. (great first outing)