It appears that the crux to the North Couloir is reaching the summit from the Cat Ears Notch. Parties appear to get sucked up a 5th class corner directly off the notch, then rappel into loose sandy gullies to get past the East Cat Ear and regain the ridge on the South side.
INSTEAD, follow a improbable-looking 6-foot wide ramp that climbs up and LEFT for 100' (4th class). Once you turn the corner (out of sight), the difficulties become third class as you cross under the NORTH side of the East Cat Ear.
DESCENT: A 3rd/4th class traverse also exists from the Notch on the North side of the West Cat Ear, gaining a 2nd/3rd class descent on sandy ledges to the Dade-Abbot Col. A mellower snow slope (up to 35 degrees) leads down to the Dade-Abbot Basin.