Downvote the DT

I’d make a five room dungeon that basically has 2-3 traps and 2-3 encounters. Since it’s only 2-3 hours you don’t want to have too much set up time of them meeting in a tavern. For a one shot sometimes it’s just fun to say “you’ve been hired to clear the old mine outside of town. The mine used to be used by the villagers as their major source of trade. But the goblins came along and stole it from them.” Then drop them off a little distance from the mine and give them a wilderness encounter before they enter it.