Reports still indicate that the Big Oak Flat Entrance will open in about an hour. So far, locals tweet that it's not yet crowded. This route would take a driver over the Tioga Pass to the Eastern Sierra. Tuolumne Meadows and Olmsted Point are accessible (after noon) from both directions.
YNP is pondering what to do about the next entrance. I suspect they'll lift the evacuation order for the Valley (so that essential personnel can return) later today or early tomorrow.
The fact that travelers are now going to be piling up at the Arches Entrance will probably persuade park administration to do something. Up until today, people were piling up in Mariposa and couldn't go beyond.