Spokane to Calgary with heavy load - best way?

Hi Eric - I am keeping my fingers crossed, but it should go fine, at least that's why I'm paying my broker hundreds of dollars. The paperwork is amazing, but again, am confident it will be okay. And for Soup, when I say 'underpowered and overloaded', I don't mean dangerously so. I can still make the steeper hills at at least 45 MPH without pushing the engine too hard. It's just that I wish I had a lot more power.