Unfortunately, yes, you did cause more damage by waiting. Inventory was very low when I searched Travelocity on May 29. If you didn't reserve on the 29th, do it today. If your friends can't do it at the same time, reserve your room and both of your parents' rooms and have them pay you back later. Your friends may not be able to stay at your hotel at this point.

Everything worked out. We booked 5 rooms at the Hotel Union Square and the 6th couple is using rewards points to stay a block away at a national chain. All within budget, surprisingly.

Glad you found a place! Best to your family. Come back after it's all over and let us know how it all went.