Camping at 27 degrees.

We are new fulltimers,with 2007 bounder class a 38v. We are trying to stick around sw p.a. till thanksgiving, they are calling for low around 27 degrees. We have ducted heat,2 furnaces,with supposed basement heat so say's owners manual. I am going to disconnect from shore water and just use fresh tank,keep heat on 70,leave luggage lights on (1156) in wet storage,leave gray water open as always & empty black then shut and add antifreeze.Should that be good enough ?Thanks Shannon.