In one instance, we did a triptych, cutting one image into three, to solve a problem in an installation (light switch).
Recently, is was a triptych that a customer wanted with interchangeable flat-mounted canvas panels that they could switch-out for the season. If the customer is willing to purchase the photo, I'm willing to listen to what they want and then sell it to them.
For my own work, I do a lot of pairing of images and then matching up multiple images that when installed, are basically diptychs and triptychs and sometimes printed on on panel of canvas or paper. Not all images will work this way, but the groupings that do and printed as a single piece look pretty nice on the wall.
Why not take an image that may work well, print either two or three panels and put it on the wall and see what you think and what your customer thinks.