Your propane runs out, and nobody's in any condition to drive
You should have checked the tank, but you didn’t. Driving is not an option, and walking to the store would take an hour. There aren't enough sides in the world to feed you all, so how do you cook those perfectly marinaded steaks?
The solution: The easiest fix is to always invite somebody old enough to drive, but not old enough to drink. If you didn’t do that, call an Uber or Lyft. Worst case, you can have the driver take you to the store and back. But some, if you call them on their way, will show up with the propane if you promise a good tip.
Margot brings a dozen extra guests... again
First: how much do we all hate Margot? Seriously. She is absolutely off the Christmas-card list this year. But her dozen uninvited friends mean you have twice as many mouths as you planned for right now, and you don't want to be rude (unlike somebody). How does everybody get fed? It’s not like Margot brought anything but a bottle of wine she’ll drink all by herself.
The solution: Cut all your steaks in half. Reform the burgers. Split the brats down the middle. Make lots of small stuff and cook it up, then serve it buffet style. Break into the snack cupboard and lay out some extra bowls of chips, crackers, Twinkies, whatever you have on hand. Worst case, you can open some cans of beans and make chili with the grilled meat in a two-stage cookout that looks like you planned it. Then lose Margot's number.