We would love to see more photos and read a travelogue about your trip! We plan on a July/August trip next year and love hearing about others trips!!
Quick travelogue -
From Federal Way, WA to Anchorage, AK. We had to do our trip quickly, and get back home, so we did it in 4.5 days, in late April. Total mileage: 2,510 miles. The farther north you go, the later the campgrounds start their season, so our options were limited once we got into northern BC, Yukon and Alaska. Many campgrounds don't open for the season until May 1 (earliest) or not officially until Labor Day weekend (especially in Alaska). Some campgrounds are open without services (open gate). We found private campgrounds were still open, with reduced rates. As you get farther north, one could even camp in the roadside pullouts, in a pinch.
We just missed a 1-2 day road closure (by a week), due to wildfire on the Alaska Highway (not the big one near Ft. McMurray - that was way to the east). Be prepared for the possibility of delays due to wildfires if you drive north through Canada and Alaska. Wildfires are definitely on the upswing over the last 10-20 years. You'll see many burned out areas from past fires & the new growth as the forest succession starts over again.
The Alaska Highway is in pretty good shape now, but it's typical to find re-paving or straightening efforts. The Yukon was particularly rough near the Alaska border with lots of gravel (for future repaving this summer) and frost heaves. These areas can really slow you down as well. If you're trying to drive the speed limit, figure 50 miles per hour for planning purposes (including short breaks during the day's drive).
We saw a lot of great wildlife: black bear, bison, deer, stone mountain sheep, Great Gray Owl, Short-eared Owl, Caribou, Dall Sheep, Porcupine, Snowshoe Hare, and Moose.
At the Alaska border, the customs agents were very serious about having me open the trailer. Once I opened it, they explained that they just wanted to check it out. They were excited to have a look and peppered me with questions.
If you can, give yourself a couple of extra days to explore in Canada. There are many great parks to explore. It would be great to have a whole summer to explore the north country. I keep thinking that I'll do the drive nice & slow one day.
Grab a copy of the Alaska Milepost for your drive as well, it's an excellent resource.