Looks like your going to have a great adventure!
Couple things you may want to consider:
Take your time getting up to British Columbia, it is still early spring up here and like most of the rest of Canada we still have snow. All the mountain passes around me just got fresh snow the last few days.
Most Campground grounds don't open up until just before Victoria Day weekend (3rd Monday in May) there are some open earlier however those are mostly in warmer and more populated areas of BC.
Some traveling idea:
At Hope B.C. Go up the Fraser Canyon Hwy 1 to Cache Creek and over to Kamloops, down the Okangan on Hwy 97 to Osoyoos ( lots or wineries in the Okanogan Valley) then Hwy 3 to Castlegar then Hwy 3-A from Castlegar up to Nelson across the Kootenay Lake Ferry (longest free ferry ride in the world) to Creston, on to Cranbrook, past Fort Steele on Hwy 95 up to Raduim Hot Springs then take hwy 93 into Kootenay National Park than into Alberta. When you pop out on the Alberta side of the Rocky Mountains you are 1/2 way between Banff and Lake Louise which are about 25 km either way. You can stay in Lake Louise and make the short 50 drive down into Banff to see the site or stay in Banff and then head back up Hwy 1 to Lake Louise, continuing on up the Ice Field Parkway to Jasper.
These are just some ideas, however I would not take Hwy from Hope BC into the interior of BC as all your going to see are a bunch of cement Guard rails on either side of the Hwy, that's my opinion anyways on that stretch of road.
Google the names of the towns and valleys I have mentioned to find interesting things around them.
Soup.