Plan on staying somewhere else, but start calling the Sheraton, Hilton, Hyatt, or Marriott everyday and seeing if they are any cancellations. Some people might drop out, and often people will book more than one room, either planning to share or as a back up, and as their plans change or they drop out, they might cancel their rooms.
As for the flight with my armor, I flew united and since I made sure that the tub I used was under the 62" rule, it was the standard $25 they charge for the first item of checked baggage. I did not get charged extra for "oversized baggage." MY first flight, neither the ticket counter nor the TSA guy really cared. For my second flight the Ticket Counter representative wanted me to check with the TSA guy becuase while it was under the over sized baggage size, it was still an unusual shape. Once again, the TSA guy didn't really care.
On both flights it does appear they opened the case, as I secured the lid with two zip ties drilled through the lid and side, and one TSA approved lock on the other side. Both times the Zip ties were cut, and on the second time I piece of paper was in the tub saying that the TSA opened the bag to examine it.
However, a trick I learned from some of the other guys in the 501st was to include a letter at the top of the luggage, explaining that the itme contained within was a replica costume, that all items were props, as well as a picture of me in the costume, front, side, and back shots. (With the 501st we can include a line about all the charity work we do, over $11 million dollars raised for charity last year, and that will actually sometimes dissuade the TSA guys from digging too deep into the tub.)