Interesting that none of their trips go into Canada. For the Northern Tier cross-U.S. trip, it's not much distance to go across the U.S.-Canada border.
One will see more interesting stuff also in Canada. For instance just less than 30 kms. north of the U.S.-Canada border by the tip of Lake Ontario, in Ontario, is the site for the book, Uncle Tom's Cabin (by Harriet Stowe)...the real place where freed slave, Josiah Benson built his place (several buildings) and also helped escaped slaves. I know...because I have a good friend who lives near the historic site. Alot of the U.S. blacks visit this famed site as the final site to freedom for Underground RR.
I realize there are the passport requirements...but no different than going over to Europe.
For the Northwest, one can take a fast ferry to Victoria, B.C. to Vancouver Island from Anacortes Island.
All along this international border crossing, cyclists usually are treated well by border authorities.