You have a good handle on the directions in my post. The route from enterprise to Edmonton is the section I have traversed many times. Unfortunately, I have never experienced the highways west of enterprise. The liard hwy is unknown to me. Im sure your van will do quite nicely. We just keep our speed to 80km/hr and the last hour is not too bad.
Bullocks fish and chips are the French fry kind, but fresh French fries. They have the potatoe punch right beside the grill and all the fish (except for arctic char) are caught right here from great slave lake!
Hope to see ya there!