I don't see what choice you have if you use these tiles. But maybe you could use a plain version around the edges so the design isn't chopped up?

I would also personally prefer a 20" tile edge on the least visible side to 10" edges on both sides of the room. Or will it be complete tiles on one side and 10" tiles on the other?

Finally, remember that people rarely look up. Even you will be too busy looking at the other pretty things in the room to notice the ceiling tiles very much. So if you do have to have a row of incomplete tiles after all, it's not a huge deal in the overall scheme of the room.

Thanks for the feedback. I'll see if we can do one cut side instead of smaller cut on each end. At least then we would have more of the dropped panel instead of small portion.