To keep it short: bring a rope. This route goes at grade 3 when the couloir isn't fully covered in snow. My buddy and I solo'd it.
My friend Karl Marrett and I went up the North Buttress Couloir this last weekend. Small avalanche debris, but otherwise very nice! The Couloir itself is decent snow with a few cm of an icy layer. Once you get to the ridge though, the snow on the west side is garbage. I'd recommend climbing directly on the ridge rather than traversing around. Bring flotation for the approach! We were postholing nearly every step!