Congrats!!! I went to Duke as an undergrad, even though the experience would not be the same, but it truly is a great environment and has lots of amazing people:)
Test day nerves a factor? Also, I think PT 82's LG was pretty easy compared to the average test... so if you're retaking this December, I'd drill LG as a top top priority!
Another thing to think about: Not sure that the admission committees of said schools are open until after New Year's. Will applications that come in on Dec. 27 be given any priority to those that come in on Jan. 2?