I got a great room in May last year... but it involved a lot of luck. Here's what happened.
You know how there are badge resales? Well there are hotel room resales too. The difference is, these resales aren't advertised. They are resales of hotel rooms that people either didn't book when they were first offered, or had to cancel. The first deadline is May 4 (for a full refund). A couple of days after that, CCI will quietly put the refunded rooms up for resale. IIRC from last year, it wasn't even announced on the CCI hotel page.
So how do you find out about this? Well last year I participated in the hotel lottery and wasn't assigned anything. My friend was assigned a Mission Valley room we didn't want/didn't book. So both of us were on an email list that was sent out informing everyone that there were resale hotel rooms.
I happened to be on my email at the time the message came in and immediately went to book. All of the downtown hotels were there, at the cheap Con rates! Now don't ask me how many rooms there were for each one, but all of the hotels had some rooms that had been refunded.
So my advice, if you want a resale hotel room, is to participate in the sale tomorrow, but don't book anything. Then make sure you are constantly checking your email from May 5 on.
HTH!