Dump a gallon of pinks stuff in each (black and grey) holding tank. Even with enclosed underbelly and ducted air blowing around the tanks, there is nothing protecting your dump valve. Warm tanks are useless if you can't dump them.
If you have by-pass valves on your water heater, maybe, leave it by-passed. Heat your water on the stove. One less thing to worry about re-winterizing.
As others have mentioned, open doors / drawers to allow warm air around plumbing lines and lots of propane. If temps are in teens and twenties, you could go through 20 lbs per day.
Bring plenty of disposable hand warmers. I have used them for thawing a dump velve (don't let them go down with the dump) and after an ice storm, I used them to get an antenna down to stored position.
Bring enough antifreeze to winterize at a moments notice. Be ready, in case the bottom drops out on the weather.
