Let's say, theoretically, you decide to mix four households instead of three for Christmas, your stasi neighbours get wind of it and report you to the police, and the police actually give a fuck and show up on your doorstep.
Do they actually have any power to enter your home and count who is there and demand proof of where they live?
And what if not everyone can even prve where they live? Say one person doesn't have any proof of address because she is the live-in girlfriend of one of the other people (so they are one household) and doesn't have a driving licence or her name on any of the bills.
Asking for a friend.