Help with cold weather tips

I plan on taking the 2013 2720 on a cold weather trip in a couple weeks. I'll have power but no water. Temps will be low 40s during the day and mid 20s at night. I plan to run an electric radiant heater on a dedicated extension cord at night instead of the propane heater. I was thinking I should leave cabinets to plumbing open at night. Any other tips? One question I have is I'll be driving over at night and should I worry about plumbing freezing up while I'm driving? Not sure what options I have. Should I empty everything out and open all valves then fill the holding tank with fresh water, but not run the water pump until I'm over there and set up? My drive is about 4 hours over a couple Cascade mountain passes. Temp will be above freezing for maybe two of the four hours.

Thanks for any tips and advice.