I have a Kona Jake the Snake with a 36/46 crankset with a 12-27 cassette. I use the bike for fireroad/singletrack use, and I'd like to set it up as a general road bike for my wife (assume that my wife fits the bike for now). Obviously, I'd switch wheels/tires as needed (i.e. cross vs. road wheels/tires). We live in a fairly hilly part of Colorado and the gearing currently is not quite high (easy) enough for my wife to get up some of the sustained 6-10% grades around here. Plus, it wouldn't hurt to have higher gearing for some single track climbs for me either.

I'd like to avoid a triple conversion and maintain the double set up. I'm thinking about adding a mtb cassette (e.g. 12-32) with a mtb rear derailleur. Does this make sense? Any thoughts?