I'm no expert, and my vaulted theater room is only 18'x15.5', but depending on the projector you'll be using (mine is a JVC RS-45) and which wall will have the screen, you could wall mount it. My screen is on one of the 18' walls with the projector mount 15' back. It ends up being about 13.5' from the lens to screen.
It took many hours of searching to find this; it seems not many people choose to mount projectors on a wall
] I paired it with the RPA bracket made specifically for the JVC.
It looks much smaller on the website than I expected; this thing is a beast. That's a good thing though, so is the JVC.
I feel very comfortable hanging a big projector on this mount because I think they were ultra conservative in their weight rating.
I'd include a picture but I'm not home; maybe later.