For all of you last minute planners (myself included), do not despair. Do not give up hope!
You can find Lodging in Yosemite Park in the summer.
Keep checking the website for the park. Take whatever you can get for the dates you need. And upgrade as availability pops up. I went from a tent to a shared bath room to a room at Yosemite Falls. They just keep charging the difference to my card.
It can be done. Good luck!
Can't wait to go back to Yosemite. I'm taking my kids on the trip my dad took me on 30 years ago. Like history repeating itself.