Mostly what I do! We get down to -30 at my place, and much colder where I use to store it for the winter. I need just a bit under 2 gallons using the winterizing bypass feature.
I have never put antifreeze in the FW tank, but In know people that do. I also had a former coworker who's husband fills the water heater totally full and leave it that way all winter. She had no clue why, but it was what he did every year.
As for the FW tank it really does not need any in it as long as you drain the tank. The little bit of water left in it does not have the destructive strength as it is just thin film. In the spring the FW tank will also be much harder to rinse out, lots of water, and time. To ensure the water is out, after my last trip, I leave the drain valve cracked open on the way home to ensure any water has a way to escape.
Our last trip is still over a month away.
Happy future Retirement