I have climbed the main gully up to Woolly Hole. It is steep, but you can climb it directly without using the ledge bypass in the Kelsey book. In 2000, there was an old frayed cable hanging of the highest pitch, but it would shred your hands without gloves. The cable may not exist any more, but either way, the wall is climbable with one short 5th class pitch.
Another possible descent route is the Pika Cirque. You can descend (or ascend) the steep SE face of North Timp into the Cirque. There is a pond at the lip of the cirque and then a waterfall below. This section is tricky when snow covered, and you had better be good at self arrest. After bypassing the waterfall, you can descend very steeply into Woolly Hole. The route down below Woolly Hole is more tricky to find from above than below.
An excellent descent would be the Cold Fusion Couloir, as long as it is snow filled. It runs just west of the North Ridge. It took me around 15-20 minutes to descend the 2500 feet from the top of the couloir to the Timpanooke road. I'm fairly confident it would be faster to descend this and walk the extra distance to the bottom of the north ridge than it would be to descend the ridge itself.