I have given this a bit of thought as we used to travel over the winter months. Don't know if we'll do that so much anymore. Our past method, however, was to turn the thermostat down to about 45 degrees and just walk away. It really didn't run that much as was demonstrated by a tiny electric bill. (We're total electric.)
In my case, I would have wanted to put in a "Tee" in the water supply lines, and maybe valves to open / close to isolate what I was doing, probably close to where the water comes into the house. (We're on city water.) For us, that's in a protected area under the house and I'm not sure it would ever freeze, even with no heat at all.
The idea would be, shut off the normal water connection and attach an RV style water pump with it's suction hose into a bucket of RV antifreeze. Then, it's a matter of keeping that bucket supplied with antifreeze as you go through the various parts of the house and get said pink liquid into the fixtures and appliances as needed to protect them. Some things, like a water heater, might be able to be drained in such a way that there would be no need for any antifreeze there at all. Toilets wouldn't need to have the tank filled with antifreeze, you'd only need to use enough to put antifreeze into the water lines and valves, and then of course enough in the drains / traps to keep those from freezing. The washing machine we had, I was able to run through "test cycles" such that I could get antifreeze into both hot and cold input lines without having to run a whole lot into it. To be honest, I never did this with a dishwasher or a refrigerator with a water dispenser but I doubt either would be terribly difficult. What I often forgot was the water filter under the sink, which I usually ended up remembering after unwinterizing the RV. If I had a refrigerator with a filter in that, it would also be something to remember, if not before winterizing, afterward when trying to get the antifreeze back out of the system. Some stuff is different, whether it has to have a filter in it to operate at all or whether it'll all work just fine with no filter installed. I've not been exposed to whole house water filters that much, or RO systems.
For a whole house, it would probably take 5 gallons pretty easily and I'd probably be inclined to have 10 or 15 gallons on hand before trying it.
Honestly, I don't think it would be that hard to do. It would take some thought, though, making sure to get everything. It would also take some planning to avoid wasting the antifreeze, thinking towards what to do first and last, how long the water lines are, that kind of thing. It's not rocket science. But not everyone would take the time to work it all out and get it done.
I did it in the RV many times. The house ain't that different, only bigger. Good luck!