Carol Hague writes

I remember reading somewhere that cacti should be left to dry out
between October and March and watered like any other plant the rest of
the time (which in my case means roughly whenever I remember...).

They can tolerate cold when bone dry, which means that if they're in a
greenhouse they need to be dry between October and March (or even
later). In a centrally heated home they can have a bit of water in the
winter (but not much as the light level means they won't be growing
much)

But some dim corner of my brain is trying to tell me that
Christmas/Easter cacti are different in some way googles

They're different in that they are not cacti ;-)

--
Kay