Last year I spent a week riding the Wing around the Yukon and Alaska. I didn't have time to go farhter north but am planning to go back as part of a big northern ride (30days) in 2008
THere has been a great thread on adventure rider about riding tin the north and the photos of the road conditions later in the post (35-50 range) give a great example of the road conditions I experienced.
Note to self next time ride a much light motorcycle
The wing never went down but there were some dicey moments in the loose wet sand and gravel
Here is a pretty good video of four old guys doing the ride
and the link to adventure rider for the whole thread