We live in a four-bedroom townhouse, with 3 bedrooms and an office. A few years ago, 14 relatives visited for Christmas brunch. A freak snowstorm found 17 of us stuck here for three days. It felt like we were under seige!
The first challenge was finding somewhere for everyone to sleep. My son moved in with my hubby and I. (Thank goodness for king-sized beds!) One kid got his bed and another slept on his bedroom floor on one of those kids "ready beds". 2 grown-ups on each of the pull-out in the living room couch and the futon in the basement, with on kid on an air matress beside each of them. 2 older kids were on air matresses in the office, and we had a family of four in my step-daughter's room - mom and dad on a queen-sized bed and their kids on the floor on a thera-rest. (SD was out of town visiting her mom.)
We had enough sleeping bags, blankets and pillows, which really helped everyone's comfort level.
Half of them were on their way to an overnight visit, so had extra clothes, toiletries, etc. The other half was out for a day trip. My brother was one of those out for a day trip. He's a really big guy so the poor guy couldn't get a change of clothes from us, and ended up washing his skivvies in the sink.
Thankfully, we always have extra toiletries on-hand. We also had a full pantry and freezer, not to mention enough Christmas dinner leftvers to last a few days, including lots of booze - phew!
The bookshelves and boardgame cupboard were crucial in keeping everyone amused, especially when the power went out. We had lots of toys, paper and crayons for the little ones. The older kids had hand-held video games and music players, and we adults played countless card games after the little ones were put to bed.
If it lasted any longer we probabyly would have had some issues, (can you say "mother-in-law?) but as it was, it was more of an adventure. The kids still talk about it.
I still think about it too. I don't host family events very often but I'm prepared when we do. All of our relatives come in from out of town so there's always a chance they'll get stuck again. Likewise, we're prepared when we visit them. Don't want to end up like my brother. He keeps an overnight bag in his car now. Bet the first thing he packed was his Fruit of the Looms.