Have you tried the 46 cm frame size? It has smaller wheels, and lower bottom bracket, and therefore lower top tube and lower standover height. With the lower BB it may also have shorter crank arms (which is a good thing, in my opinion). If the shorter reach makes it feels cramped, you can always use a longer stem.
Looking at the geometry
here, there's no sizes listed for the crank arms, so they're all likely 170. Bottom bracket height is the same for all sizes, and the wheels are listed as 650 x 47. Looks like the difference is in the head tube and seat tube lengths. The top tube is quite a bit shorter, which is one of the big issues for me. A longer stem can only do so much.