I live in NE PA.
From late Oct to late Dec I just drain the lines, blow them out with about 20psi from my garage air compressor & leave the faucets open.
Over 20 yrs & four different RVs I haven’t had a problem.
Up here until late Dec it does drop below 32f but never long enough to be a concern to me.
Each person has their own comfort level with regard to cold weather preparedness.
“You” have to do what will help “you” sleep at night.
We camp in our 5er from late March to late Dec.
Dave, Judy & Daisy May
2010 Sierra 356RL
2011 Silverado 2500 4WD, LT, Ext Cab, LB
Duramax 6.6L V8 Turbo Diesel
Allison 1000 6-Speed Automatic Transmission