Southern BC is where you can make some time. Stick to #5, it is 4 lanes all the way to Kamloops and barely any traffic. After that you will be slowing. The roads in BC north of there are no better than in Alaska. There is always construction in both places. The only reason you will go slower in AK is the traffic. I drove from Anchorage to Seattle in 10 days once with pets and kids, camping at night. We took one rest day at Liard Hot Springs. Didn't push, but I would have taken longer if I didn't have to report for a new job and get the kids in school. BC is just as pretty as AK, don't rush through it.