Gary, if I recall correctly, most of the road to the falls does not pass under cliffs or steep hills. (I could be wrong.) . So there may not be much avalanche danger, unless you get really close to the falls themselves.
However, if it is 16 km round trip from the plowed road (as Dave indicates), that is way too far for snowshoes. My maximum on snowshoes is about 10 km per day, depending on the snow. Deep, soft powder will make it much harder. But an icy crust can be a lot better, if it does not break underfoot!
In the Sierras, we have a real problem with clumping -- the snow is so warm and wet that it packs under the claw, and pretty soon you are hiking on a bowling ball. Not fun.