I just winterized last night. I bought 6 gallons and only used about 2. I drained then used a compressor to blow the lines then ran rv anti freeze threw the lines. I did the outside shower also. The low point drains on mine are clear under the middle by the rear axles. I might but a elbow on those and move them so I don't have to crawl all the way under just to open those valves. IDK what these manufacturers are thinking when they do some of this stuff.
2016 Vengeance 320A
2015 Chevy 2500HD LT 6.6L 4x4 ccsb Z71 trim
2012 HD Electra Glide
Andersen Ultimate Aluminum fifth wheel hitch
Nights camped 2015-didn't count
Nights camped 2016-41...so far