Cannas like a lot of sun and moisture. What about aucuba japonica? They are drought tolerant once established

Here is a link that might be useful: aucuba japonica

Yeah cannas pretty much like the opposite of what that space could provide.
I wonder how cast iron plants would do? They should survive the winter and they like the shade and can handle dry weather especially in the winter.
Other plants could be ferns, but they stay small.
You could plant a windmill palm. They dont mind the shade or being dry (as long as its not bone dry). They grow slow in shade, but I think look there best in shade.
Good luck!

Aucuba japonica is definitely a possibility, as it is shade-tolerant, drought-tolerant, evergreen and moderately tropical-looking. Personally, I think the plain green forms are far more handsome than the spotted ones, but the latter do help brighten up a shaded spot.

Fatsia japonica is definitely more exotic-looking than many of the other choices for dry shade, and is hardier than most people think. But large plants are hard to come by and will require several years to reach 4-5 feet, especially in dry soil. They are shade-loving and drought-tolerant but not as hardy as Aucuba, so will require a sheltered location and possibly protection in their first year. They can also scorch in the winter if planted under deciduous trees where they will receive winter sun.

I've been growing Aspidistra elatior (cast iron plant) for about 7 years and while it has been quite hardy for me, it tends to look pretty ragged by spring (snow and winter sun and wind are its enemies) and doesn't put out new foliage until early summer. Also, it won't provide the height you're looking for--my plants have never gotten more than about 2-3 feet tall.