I am in Bakersfield, so pretty close to the Grapevine.
It is noon on Friday (38 degrees here according to the news) and the Grapevine is open BUT..... it is raining here and snowing in the mountains (Tehachapi is getting a lot from what people are saying). So do not expect to go over Highway 58 on your way to Disney if they do end up closing the Grapevine (which I think will happen soon). Will try to post information here if I hear they close the Grapevine or start escorting.....