I haven't ridden the Cassier Hwy, just the Alaskan Hwy. Everyone told me to take the Cassier though. Supposed to be way more scenic (if that's possible!), More bears, and more remote. Liard Hot Springs in northern BC is a must to stop at if you take the Alaska hwy route.
By the time you get to northern BC and the Yukon, it gets very remote. Sometimes days between towns with a store. EVERY SINGLE TIME I stopped to fix a flat up there, a car pulled over and asked if I needed help or wanted any water or food. EVERY time. Most people have salmon!
There's a lot of abandoned houses along the Alaska hwy in BC and the Yukon. Good place to camp, you don't have to string your food in a tree.
Under bridges, tie a rope with your food bag hanging on one side, sleep on the other. Cook and eat on the side with your food.