FWIW, we have 25''x16' Sotar tubes with the equivalent of a 72'' x 120'' (41.5'' between the tubes) frame and in all of the rivers we've run, I've never felt like it was too wide. Another thing to consider is that reducing the width affects drybox width and other gear carrying ability, but I have been known to overload our cat a few times.
This is where the no cooler, no beer, freeze dried foodies jump in and say you don't need all that crap. (said with tongue in cheek)
I'm thinking forget cutting the yokes and just buy narrower yokes if that's the way you decide to go. Oh, and you may need new shorter oars as well.
We've had our cat on the MF, Main, WW, Yampa, Owyhee, etc. at all of the various water levels.