2 years ago 4 of us were in Alaska for some military training. We had a weekend off and rented some 800GS Adventures. Did 900 miles in a weekend. From Fairbanks to Valdez and across the Denali Highway. Had an absolute blast. We rented from a Alaskan Adventure Riders in Fairbanks. I would not recommend renting from them. The guy claimed we did a lot of off roading (we didn't do any) and charged our credit cards several hundred dollars each for repairs a couple of days later. He claimed his mechanic told him that there was a lot wrong with the bikes. We talked to his mechanic and AAR was lying to us about the repairs. Disputed the charges with our credit card companies and got our money back.
I just bought a 2006 R1200GS Adventure to make a trip up to Purdhoe Bay. Right now we're planning on summer 2018 for the trip as some of our group will be deployed next summer. From Wisconsin I'm thinking of heading up to Winnipeg, head west to BC and north to AK. On the return trip head into Montana and make our way east through the bad lands of South Dakota. It's been fun looking at all the information out there about the adventure north.