Oh darn!! Maybe a reservation will open up the night before as they often do, then you can add it to earlier-expiring ticket, then drop the other one. I don’t know if the system puts a dropped reservation right back out there, so I would be afraid to drop the one you have first and hope you can pick it up. I will say that sometimes the reservation calendar shows “No reservations” but then when you actually click the date and try to make it, it might go through. Maybe that would work? Pixie dust to you!