Thanks for the recommendation! I tried both, but sadly it didn't work.
I could extract the ppd file from the MacOS driver, but I still need to substitute some OS specific paths that lead to executable files and icc profiles, like *cupsFilter: "application/vnd.cups-raster 0 /Library/Printers/Canon/BJPrinter/Filters/Raster2CanonIJ/Raster2CanonIJS.bundle/Contents/MacOS/Raster2CanonIJS". Not that many, just two or three. I will most likely try to install the drivers on a MacOS VM and see if I can extract those files and place them in a Linux-specific cups directory (/usr/lib/cups or something). I think so far the odds are even.
Update: It looks like I have all the binary files with me. Raster2CanonIJS, Command2CanonIJ, the ICC profiles and whatnot. I'm now looking for some guidance on where I should place those files on Linux, that would belong in /Library/Printers/Canon/..., etc. on MacOS.