Prior to our TCer ownership, we purchased a Thetford PP for traveling in our Suburban. After having a TCer, we thought we would never use the PP again.
However, last December, we did a road trip in our TCer. We left it winterized and carried our drinking water in the truck. In extremely cold temps, we put the PP in the floor of the crew cab and in the TCer at night.
It worked out really well and not having to worry about any pipes freezing was a real plus.