At the Q&A, Goddard was asked how he came up with the story. He said he was on a trip with his wife, writer Caroline Williams (who wrote for The Office, Arrested Development, Modern Family and others), when he said he'd love to write a movie about a group of people who just get together in a room and talk. She asked what he'd call it, and at that moment they passed a rundown motel. He looked at the place and replied, "Bad Times at the El Royale." This most-definitely isn't people getting together to just talk, and the hotel isn't rundown -- though it's seen much better times. But that's sort of the sensibility of the film, a group of people who are stuck together at an abandoned hotel in the middle of nowhere -- and things go off the rails.
Here's the trailer. It actually gives a good sense of the movie, though not a full idea of how sardonically funny it is at times. (The use in the trailer of a Franki Vallie song is especially inspired, particularly with its opening line. I'm not even sure if the song is used in the movie -- it probably is, since there's a lot of period music -- though it fits creating a sense of the whimsy and ironies of the movie well.) And of course, it doesn't give away how often the story takes a left-turn to surprise you -- though given how intentionally disjointed the trailer is, you probably can get an idea of that.
I'll also toss in a scene, to give a sense of a lot of the thoughtful pacing. The quiet here isn't necessarily like all of the film, most especially the second half, though the performances are like this throughout, where you almost see people thinking before they talk, and sense that there's more going on with them than they're saying. Here, Jeff Bridges has arrive to find Jon Hamm ringing the bell at the front desk to get a clerk for a long time with no luck, nor does he have any luck, when Cynthia Erivo decides to bypass the bell and get Lewis Pullman's attention.