In the same shoes and from what I understand it is mostly paved with exception of Top of the world (50-60mi) and North Slope. Both hardpack perfectly doable on street tires, if it doesn't rain. If it rains you have a thin layer of mud on top and puddles in potholes.
New or not your TKC80 are not likely to make round trip due to distance and chip and tar abrasive pavement.
We fitted Wee with set of E-07 Dakar which should make the round trip, and my son's bike has rear E07 and front Shinko 705. 705 will make the distance, but the choice of rubber in 17" very limited, so if it gets wet we will have to either leave his bike behind in Fairbanks, change the plans and go south first or get 17" TKC80 front swap locally.
K60 Scout rear/TKC80 front are popular, but wouldn't work for us with 12k trip. Besides Mitas E07 last as long as Scout and not as scary in wet. For grip front TKC80 or Shinko 804, Mitas E-10 or Sava MC60 would be a better choice but E07 will do the distance and will have better road manners.