It depends on what's most important to you. So, if you have a downtown hotel, it might be worth it to you to look outside the housing block on normal channels for just the Wednesday night, sleep there for one night, and then go to you original hotel. If you don't care as much where you are, or if you are already needing to drive in, you can check for what's available with your new parameters and see if you like what's there. You can still modify your reservation (including the hotel where you will be staying) for free until July 17, and the modification doesn't happen until you agree to it, so you can click on "edit" for your current reservation to see what else is available.
Good luck!