I'm thinking hard about this...we just got back from a ride out in the Iowa countryside...lots and lots of hills...had to get down to our lowest gear several times to keep going...Holly asked to walk one hill, but we made it. OTOH, we hit 33.5 mph coasting downhill once and several times over 30 mph.
Hopefully, a clipless system would make part of the hills and flats easier. Probably riding more often would help, too
Dan