Try this out for size. I did this a couple of weeks ago.
Take Hwy 66 (Green Springs HWY) off of I5 about 13 miles south of Medford, to hwy 140 east to hwy 39 south to hwy 139 south to 36 / 395 south to Reno.
The section between I5 and 140 has fantastic twisties. The route takes you through forest, by lakes, near lava beds, farming. It was well worth the extra time.