My current plan is to drive in shifts from VA to Portal, ND. We've been through that area twice before. Once we hit Canada, we will restrict travel to during daylight only and hope to knock out 600+ miles per day until we get to Dawson Creek. From there on to Ninilchik, no more than 250-400 miles a day, while we soak up the scenery. When we've traveled before, if we get delayed, I just do a 10-15 hour day (or night) or two and get us back onto schedule.
We are making only the most critical reservations and trying to place them in the middle of our time line. The rest is completely flexible. No one will be broken hearted if a few stops have to be skipped. If the nay sayers are right, we will make the best of it in the Yukon or BC.
Thanks for your encouragement and insights!