At Bo Kluea you can head west on highway 1256 (yet to be explored) but I continue down highway 1081 towards Nan. If you check out the Google maps sections of this road they look quite different to the video and you can see from the video large sections of this part of 1081 are new and smooth and just laid down. You can get your head down onto the groove and enjoy the ride. There are one or two sections where the road is not finished but by the time you are watching/reading this I think they will be finished.
Google map links for exact locations on this video: start of video / finish of video
Highway 1081 starts up north in Chaloem Phra Kiat and videos from there can be found here: Part 1 and Part 2 (which ends where this one starts)
Ride carefully and always within your ability. The video shows speed (it is not completely accurate and has some inconsistencies), elevation, heading, distance along the route and a squiggly line representing the road with a red dot showing the current location. This video was shot in April 2014 and roads in Thailand do change over the years, a once pristine section of tarmac can degrade and likewise a bad section can be resurfaced and become as smooth as silk! Leave a comment if you have an up to date report.
You can find excellent bike reports and information of northland Thailand over at Golden Triangle Riders