Hi Tammy!
So, taking a last minute trip huh? Sometimes, I feel I should plan a last minute trip vs. months in advance, just so I don't have to count down the days (every day) to the next Disney trip, which can take agonizingly long :-)
As I've told friends and guests in the past, any restaurant will fit you in if they can. The problem is, sometimes that can be a big IF. If you arrive and they're already pretty packed, they may not have a seat for you. Also, the time of the year (near Christmas) is very tough. But who knows? Perhaps luck is on your side :-)
But if this is really a place you want, I would keep trying periodically to see if anything comes up. Also, I would call vs. trying to see times online. Sometimes the refresh rates on the web site can take longer, while the reservation agent can look at the whole schedule for that day all at once.
Good Luck! Hope it all works out for you!