North to Alaska
That is a great ride. A group of us on 06 and 07 1200 GS did the ride in 2008. Absolutely the ride of a lifetime. As part of your prep, I highly recommend you get a current copy of Mile Marker. Assuming it is still the go to guide for Alaska travel, it lists some very useful information concerning road conditions, fuel stops, etc.
Be prepared for all weather; cold, hot and rain.
Enjoy the adventure.