However, as of this writing, there are actually some rooms available at both the Disneyland Hotel and Grand Californian for that night.
Last week, Polygon reported that all three of the Disneyland Resort hotels, the Disneyland Hotel, Paradise Pier Hotel, and Grand Californian Hotel & Spa, were sold out for the night before the opening of Galaxy’s Edge, the night of May 30.
Either way, if they were sold out before, you can be sure there aren’t many rooms left right now.
It’s possible that some cancellations have taken place, or that rooms that were not expected to be available, due to refurbishments or whatever, have now opened up.