I am currently working on this Summer's 6,000 mile loop from Orlando to the Bay of Fundy and back and am using Good Sam Trip planner.
I see your GS membership on your profile so just go to the www.goodsamclub.com website and give it a try (log in first if you have not already so you can save your work). The new version has some quirks, but you can adjust routes and it will provide low clearance, propane restriction, and other warnings if you turn that feature on.
I'm finding it about as useful as any I have tried. I do wish I could print maps, particularly large scale maps of in-town twists and turns, but havn't found a way yet.
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