You kind of answered your own question
One thing I'd be concerned about is whether or not you can easily make it from the Rock Springs supercharger to Pocatello. That's a long stretch and it could be cold and/or windy. If you go through Jackson, you'd make it easily, but that is more like an hour detour than 15 minutes.
Also, I kind of like the stretch of interstate between Evanston and Ogden. You'd be missing that by taking the northern route. Also, the roads you'd be on in SW WY aren't particularly scenic if you went from Rock Springs to Pocatello, so it might not be worth it. Interstate driving with Autopilot is also much easier than driving on those 2-lane roads.
Maybe go off the interstate on the way there, and stay on the interstate on the way home? That way you see more. Also, Pocatello to Rock Springs is much harder to do on a single charge than Rock Springs to Pocatello due to the elevation change.