I will be there on Sat, 6/18 with a friend. We weren't able to reserve a campsite, but the ranger mentioned it shouldn't be a huge issue to get a first-come one either at the portal or at the lower camp. We were planning on getting on the trail around 4am, taking the traditional switchback route up, and hope to be back to the car by 6pm.
Just the two of us, so if you'd like to join us, we'll be happy to provide some company for the day. Just reply and I'll check the board tomorrow am before we head out.