There is always parking, it depends how far down the road you may end up.
I believe you have a day hike permit, correct?
Actually, I will be up there the whole week prior to and leaving on Monday. As a family, my father started taking us up to the Portal since the early 50's And, back in 87, my brother and Doug who owns the Portal store both wanted to buy it. Doug won out, and it was the best. Doug is amazing.
Just a little more info on the Ravine. Most people are unaware that it exists. There are about 20 sites and I have never seen more than half a dozen or more people camped there. Now, having said that you do have to carry your stuff in and it is, as advertised one night only, but from my perspective, no one checks because it is rarely used.
You can access the Ravine either via the overflow parking lot, or the road. Just check it out and see, one, which is the best approach.
I will be up there memorial Weekend, at campsite 31.
I usually spend the week hiking at Onion Valley, Horseshoe Meadows and maybe Meysan lakes.
This will be my 57 year hiking in the Sierras.