Generally the road is well maintained and kept fairly clear even during a snow storm. If you do happen upon a storm you can just wait a couple days before you proceed. Once you hit Bishop the chance of snow drops significantly.
395 is generally an easy drive with longish 7% grade down into Bishop. As you turn off 395 the approach to Death Valley has grades approaching 10% and curves that can put you down below 35 mph. The road itself is fine... just allow extra time for descending cautiously.
Death Valley info from a local:
http://www.maturango.org/janetmuseumpages/deathvalley/DeathValley.html