Most climbs can be performed in those gears. For any climb you cannot do or suffer hardcore on: go as high as you can go and suffer, suffer, suffer, and then descend down to the bottom, when you get to the bottom, turn around and head back up. Repeat a few times for each climb and eventually you'll be able to conquer them. Establishing a better engine is more efficient than changing your gearing for only a few months of crawling up a short climb at a comfortable cadence, and then want the higher gears back.