I also heard that a Lubavitcher might make you keep P"Y and C"Y in his house and not decorate his sukkah. Not sure what your point is. His house, his rules.
This story is so absurd that I don't even believe it. Sleeping in the Sukkah is a doryasa and in clear mishnayos without any cholek. During the generations people adopted leniencies and there's various limudei zchus in the major Achronim - cold, איש ואשתו etc. In Lubavitch the obvious reason was that sleeping in the Russian cold was likely Sakunes Nefoshes, and naturally there were given simuchin for it al pi pnimius too. But to host someone on the condition of not sleeping in the sukkah is beyond absurd, I don't believe it actually happened.