From memory, it could run on a 286. Here is this version running on a NEC V20 at 9.55 MHz, an Intel 8088 clone, but was closer to the 80188 : https://twitter.com/Jameshhoward/status/1612900164745981953
However... there is a little known game that id Software did release that would run on an 8088. It's called Catacomb 3-D[1]. It was basically Wolfenstein with goblins and skeletons. Pretty sure that engine went on to become Wolf3d.
Despite the Wikipedia page saying it runs on a EGA I had a CGA monitor and was running it. Thinking I might be losing my mind I downloaded the source code on archive.org[2] and sure enough there is reference to CGA code all over the place.
The dithering (on a VGA card and modern LCD) sort of makes it hard to view; an EGA port might be interesting as 16 colours might be enough to make it workable without dithering. Although if they're using 2x2 blocks for dithering, they'd be effectively cutting the number of "pixels" to render by a factor of four, and that might make it viable.