Here is an outside-the-box idea for ya.
If your crank bolt pattern works with this - you can get a Mountain Tamer (link below) that adds a smaller chain ring. I have this set up on my touring bike making a triple in to a quad. I forget what the tooth count is that I am using now, I want to say maybe 22-24. I was using the tiny 17t one for a few years. I rarely ever use the "granny gear" and the jump was astronomical from the small normal chain ring to the 17t, so this past winter I put the bigger of the rings on. Truth be told - without panniers on the front I've flipped backwards trying to get up some steep hills.
If you can't tell, I'd much rather have too many gears than not enough. There is a point, though, of diminishing returns. I neglected to do a terrain analysis of a trip I did in November. There was a significant climb through a switch back on the route. I could see it from a ways away, but there weren't any other roads within reasonable riding distance (and not without their own hills) from where I was so I went for it. Even though I had the gearing, I didn't have the energy to blast up the whole hill so I stopped. The hill was so steep I could not get back on the bike so I had to walk up it - very slowly with a heavy bike + gear.
Mountain Tamer Triple adapter - LOWER GEARS for bikes of all kinds