If you really want a caravan, go for it.
We go every year as we summer on the Kenai, and we lived there in the '60's and '70's. Sue T. lives near Whithorse, and there are others who live in Alaska and comment here.
The caravans charge a lot of money, last I looked it was $5,000 and up. For that you get paid campground fees, which average about $35 a night with full hookups, except only 30 amp service and a central sewer dump is common. They have a rigid schedule, but is is reasonable and based on the popular attractions and many years of refinement. Your fee includes some attractions. There are also periodic planned social events, some of which you must contribute food and such to. Put another way, they charge you 2X+ the cost of the included amenities at retail.
The social structure of caravans is not, in my opinion of watching them in campgrounds, friendly to the travel trailer. Large motorhomes rule the roost. Others experience may vary wildly, it is just what has been observed.
The itinerary does not start until Dawson Creek, and usually ends near there. Lots to see and do between AZ and Dawson Creek. Also, elapsed time and the dates are important.
OK, I'm sort of down on caravans, for the reasons stated. A lot of folks like them based on their frequency and large numbers. Most of them drive diesel pushers.
It is a wonderful trip, however you decide to go.