I was up Mammoth Gulch on Saturday- couldn't even get to the big campsite before the first fork in the road. Though on my way down there were some pretty big Jeeps headed up, so who knows they could have blasted up a bit more. But as we all know it can be dry as can be down there and still drifty up top, so I'm sure it'll be a while.
That's ok though, snow makes easy trails more challenging. As long as everyone respects that and doesn't just try to drive around the drifts.