The Tesla website SC map at
Supercharger | Tesla Motors shows two Superchargers coming to highway 80 by the end of this year (move the slider bar at the bottom of the map to see them), probably in or close to Winemucca and Elko. It's only 165 miles from Reno to Winemucca, and 124 miles from Winemucca to Elko. Easy.
Elko to Salt Lake is 230 miles but it's pretty flat so if you keep it to 65mph or less and start with a full charge you should be okay.
Nothing is shown for highway 50 in Nevada and I doubt Tesla has plans for any SCs on that route.