I've spent the last two Thanksgivings in Georgia, granted they were with other Northern transplants and their Southern-born children, but I've still noticed some distinct differences between Thanksgiving up North and down South.
The first thing I noticed is that Southerners pronounce the word "Thanksgiving" differently and I don't just mean they say it in a Southern twang or drawl. Southerners make Thanksgiving into a verb and distinctly separate it into two words, "I'm spending thanks giving in Athens with my parents." In contrast Northerners pronounce Thanksgiving as a one-word noun, "My parents are hosting Thanksgiving in Pennsylvania." It is a subtle difference, but it's there.