I may be one of the few who knows where the Devils Dance Floor is found.
I think you want to look at a different route. Drive from Crane Flat toward Yosemite Valley. When you get around the turnoff to Foresta, there is a trailhead. I think the eastward trail may be called the El Capitan Trail. Now, there is a certain amount of up and down, but the trail might be a more direct way of getting there, as opposed to Crane Flat. Honestly, I'm not sure how you would get there from Crane Flat. You could go east on the Tioga Road (unplowed) past the gate and up to the turnoff to Tamarack Flat, then down the unplowed access road to the campground, and then through the woods to the Devils Dance Floor.
I'm not sure that the Devils Dance Floor would be that great of a place to camp in the winter. It is a bald granite dome.
You might try going from the Valley up the Snow Creek Switchback Trail. You could could camp in the woods near the Snow Creek Cabin.