Realize this is an old post BUT, get real. Hello it is oversold already and that doesn't count other non-revs. The answer is to start standing by a few days early. It's cheaper to stay in a hotel than lose an expensive prepurchased ticket. Always have a few days sightseeing in the backup plan just in case it happens. Book hotels with booking.com. You can book until noon day of arrival. Good to know if you really don't know which day you will be arriving.