Haven't been up there for a couple weeks, but I do know that when the Rangers say it's "closed" they mean there is a sign saying "Closed". One can easily drive past the sign and continue up the road. In the beginning of march I drove to around 6900ft before I hit snow. I suspect you may be able to drive to nearly 8000ft, when the road begins to head off the Eastern slopes and into Onion Valley. Good luck.
Eric J Lee