Picard is right, traffic is always stupid around here now.
Aside from Picard's northern route, you should hit up the eastern border crossings like Ferndale/Abbotsford or even 264th on the way back. Buy yourself a good map then find the route along the Fraser river from Fort Langley to about 256th. Turn right on 256th, then follow the roads south until you hit the border. My numbers aren't exact, but a map should allow you to find a route that goes through. Basically all of the roads in the area are still rural, and beautiful to drive.
Be careful though, livestock and pedestrians still roam free sometimes.