Just got back from alaska. No joke about 100 miles taking 4 hours. The road from beaver creek to Haines jct in the yukon is pretty beat up, we averaged 25-30 mph on that segment. With your setup just take it slow. The potholes and frost heaves can really shake things up. The road construction will slow you down a lot too.
One thing is to get fuel in Fort Nelson. Fuel between ft nelson and Watson lake is expensive (> $1.60 PER LITER).
Have fun and enjoy Canada. It is a fun place. Just remember no fruit, vegi or taters at either border (US or Canada).