"Everybody" is technically singular while "their" is plural. It should say "Everybody is at his or her cabin". I sometimes don't use proper grammar because it sounds weird.
I'm lucky this summmer, werkin on my parents house at the lake, staying in a charming little cabin on top of a hill..
[deleted]
2 ups, 8y
That's the ticket. Stay in someone else's cabin.
[deleted]
1 up, 8y
That looks beautiful. My husband and I rented a little "rustic" cabin for a few days one summer. He kept looking around and saying "I am pretty sure this is an old wooden grain bin" The funniest part is that I think he was right. There was a group of about 10 of them. They just had to put a window and a door in each one.