2015 28dbud here. I drain the hot water tank, pull the anode to check it, and switch the bypass valves on the back of the tank. Use a clean rag to wick the standing water out of the tank through the anode hole. Use compressed air on the outside hose hookup. I start with the kitchen sink, then bathroom, then vanity opening one at a time to blow out. Then double check a 2nd time. Finally open the low point drains behind the left wheels and blow air through there. I put the bypass on the pump to pump rv antifreeze in. Stick the hose in a bottle and kick on the pump. Start farthest to closest opening faucets one at a time. Let them run enough to fill the drain p traps with antifreeze while I'm at it. Drain black and Grey tanks. If powered and your fresh tank is heated leave the fresh alone. If not there should be a drain behind the right wheels. Takes me about 30 minutes and approximately 3 gallons. I read don't put antifreeze in the hot water tank so right or wrong, I just make sure it drains and doesn't hold water. Winterized mine 6 times last year between outings with no problems. Disclaimer - your mileage may vary and if you freeze a pipe its not my fault. LOL. Good luck and have fun.
2015 Wildwood 28DBUD
2004 Silverado 2500HD tv
Old enough to know better, but young enough to do it anyway.