This sounds like a great trip.
Buy the Milepost. It is worth whatever they are charging for it now. I drove to Fairbanks from Boston to Alaska in 1987 and all my friends are tired of hearing my stories. The milepost really tells you about the high way and expected services. Fuel up as you can, there are few long stretches but normally services are available on regular basis. Leaving from Georgia the Tetons, Yellowstone glacier national park are all possible. Even the badlands and black hills can be routed in. In Canada , Calgary, banff, jasper are great stops. Liard hot spring great place to unwind.
It took me three months and I could have taken more time amazing beautiful continent we live on.
Are you bringing a spare tire.? This would probably be the one place that I would get and carry a spare. I would not want to sit for a week on the side of the road waiting for specific tire to arrive.
Best wishes for a great trip.