Might consider keeping the furnace on about 40-45 to help warm the basement/belly area. You will need good batteries to do this, otherwise, drain up and winterize for the trip. We just traveled from CO to UT to NM to OKC--no freezing even in 15d temps.
2016 Tiffin 40 QBH
2015 38RSSA, traded
2005 TK3 #1869, 10 yrs of memories,
2017 F450 KR--one more Ford is it
2009 F450 4x4-died; 2010 F450-retired