I would suggest US 14 to Greybull, US 20 south to Worland, US 16 east to Buffalo. Ten Sleep is a neat little town, worthy of a stop to stretch the legs. Ten Sleep to Buffalo is not a difficult drive at all, though it's a bit of a climb from west to east, but no tight curves that would be a problem for your rig.
One thing to be aware of...the route between Buffalo and Ten Sleep is popular with motorcyclists, so just a heads up to keep an eye out. One time on that route heading east to west, a bunch of them came up on me from behind and passed me on a curve. A bit unnerving.