I always go to a party that some friends have every year. When I say party, it is more 'open house' with lots of people in different rooms (big house) mainly talking politics / music / environment / ... ; whatever takes your fancy in fact. There will be lots of simple finger buffet food and you take your own booze. It is all very informal and we don't stop for midnight. People will fall asleep on the floors and furniture, some will drift off home, some will be there for the mega cooked breakfast at 10 in the morning. I might take the bivvy bag this year and kip in the garden.