If you can't get an earlier reservation, I would also try showing up early. If you don't have other plans and are staying there, it can't hurt to try. With all of the cancellations and no-shows, you never know when you might be able to walk-right in. We're local and you would be surprised how many times we have walked right up to the podium and got in when the ADR system and the cast members at the central dining availability window within the park say that nothing is available.