Go for it. Mine use them so its not a waste of money. Also I figured would help keep them warm since tempatures will be coming down in the next coming weeks.
I also put twigs in there for them to chew on. Momma 2 had the twigs in the nest box with a elaborate nest. No babies but either tonight or next two days.
Probably going to get one for the male tub. That way they can sleep together and help warm thier selves.