Await Further Instructions (2018)

A family (mum, dad, son, daughter and their other halves) get together for what should be a happy Christmas but almost immediately it's obvious there's a clash of personalities between, well, everyone.
This is made worse on the first night when the house appears to be coated in an impenetrable black substance.
A message appears on the TV telling them they are under quarantine and to await further instructions, funnily enough.

It all goes completely to bollocks and almost everyone ends up dead.

Perfect Christmas film, really!