Thank you for the credit Stan!
A couple added tips....
I did it by myself. To make that easy, I would pour the antifreeze into a large bucket. I zip tied weight to the bucket end of the hose to keep it in the bottom of the bucket. Then I could go inside and open all the faucets my self. Because of the Splendide, the HydroHot and all the long Beaver pipes it took closer to 4.5 gallons. (Our new "motorcabin" will only take a gallon!)
Ice makers usually have a carbon filter that will be become useless with any antifreeze. There is also a plastic valve behind the outdoor refrigerator access panel. My filter had quick connects. I unscrewed the inlet for the plastic valve and disconnected the filter. Gravity seemed to drain out enough water so it would not freeze. Check the instruction book for the fridge.
Some have drinking water filters installed either at the inlet to the motorhome or under the sink. If they are carbon, they have to be bypassed or replaced after the system is fully flushed.
If you have a Splendide washer dryer, it has to be winterized too. There were "old" instructions and "revised" instructions. Essentially you make certain settings and run it until there is antifreeze in the drain pump. Reading the Splendide instructions takes longer than doing it.
Some say you need to worry about the city water inlet. With the pump on and all the other faucets off, you should be able to depress a part in the center that allows some antifreeze to squirt out.
Don't forget the outside shower.
WalMart always seems to have the cheapest price for antifreeze. Near Tacoma it would vary from about $3.50 to as low as $2.50 when the camping stores would want near $5.
Once I did it a few times and had the right equipment lined up, it only took about 15 minutes. I normally kept the Beaver plugged in with the HydroHot electric on because we liked to use it in the winter. However, sometimes we would see some colder than usual weather and I would fear power outages. If it got cold and the power went out, it would have cost $8K or so for a HydroHot. So, I winterized many times when I didn't need to.