Unless things have changed the park will be at least partially open. Tioga Pass will still be snowed in so no Tuolumne Meadows access. I've camped in the snow at Upper Pine CG. You need to check which campgrounds are open but you should find a spot in the valley. Trails may be snowed in too. There is a downhill ski site up at Glacier Point, IIRC it's called Badger Pass, so that will be open and there are cross country skiing sites around the park. That's a good place to learn how and you can rent gear there and take classes. I also took a snow survival class there which was very informative and fun.
