It will be quite the trip.
Can’t recommend where to stay with your rig. But along the way thru Canada and AK, there are generally no lack of pull outs to stop and spend the night at as needed.
And don’t know what you’re into so hard to recommend the sights. But you’ve hit on all the popular spots. Idk about getting reservations for camping, this late and with your requirements.
And not to get off topic, or suggestive, but that is a long trip and thousands of miles of bad roads and slow going with a big 5ver like that. Totally do able. Many haul trailers up and back, but having made the route a couple times and lived up there for a while, I wouldn’t haul our big toyhauler up there (a lot smaller than your 5ver). I would want a much smaller trailer, or another option.
But we prefer out of the way locations and exploring, which is imo, the majority of the adventure to be had when the majority of the territory you’re traveling through is uninhabited.
You’ll want to plan base camps so to speak, to set up for a period of time at and then do whatever you plan to in that particular area.
Just my 2c. Awesome trip either way!