yes winterize your cabin. trailer, RV with windsheild wash -40°c ( PVC is resistant to many alcohols, fats, oils and aromatic free petrol. It is also resistant to most common corroding agents including inorganic acids, alkalis and salts. However, PVC should not be used with esters, ketones, ethers and aromatic or chlorinated hydrocarbons) and air compreessor that will connect to water inlet
turn off water and disconnect water connnection than add air compressor to plumping side with a regulator set to 15 Lbs, presserize system.
start open hot taps that are near compressor and work your way to the longest tap, then hot taps: and close all hot taps if nothing comes out, open drain on hot water tank flush the water remaining in tank by close valve/open valve( by build up pressure then open valve on tank drain till air comes). toilet flush it and open / close to drain water from lines after that go fill all sink traps, drains and toilet with anti-freeze.
all set for winter and ready to go in the spring.
Note Diagram for permanent set up can use a 12vdc or 120vac compressor and with a "T" valve to keep water out of compressor more safer for a check valve may leak