We have a lot of experience with this. We live in cold Minnesota and use our MH all winter as our mobile ski chalet. Part of what makes this so easy to do is that we have it sitting right next to our garage, at home.
We keep it winterized, both drain and blow the lines as well as the pink stuff.
We run the furnace and portable Mr. Big Buddy starting either the night before or I get up really early (3-4 AM) and start them. Depends on how cold it is. But with you being in GA, I'm sure our definition on 'cold' would be different :-)
Once we get to the ski area we use the big buddy only as there is plenty of outside air getting in to the interior via the door opening constantly ... we also have the required openings for fresh air to run the big buddy inside. Furnace only at night, but we rarely stay in it overnight, during the winter.
Also, run the fridge.
We fill a 5 gallon water cooler with water. We use this for coffee, tea, hot chocolate, and cooking.
If we have to use the toilet, it is #1 only. 'Flush' with the pink stuff. The black tank is no problem, as it just has a couple inches of pee and pink stuff mixed in and there is plenty of room for expansion if it does freeze.
We take our pizza oven along and run the genny while cooking pizzas and also cook outside on the Coleman stove and oven.
This works for us to just stay winterized and deal with the hassles of the big buddy and water cooler. It is doable either way, but this is the way we do winter use. Good luck!
