I have not heard anything from them yet either, except for an email saying my application was complete (around Sept 25). That email said they would send out interview invites by/around late December!
The day is filled with tons of opportunities to interview the school as well so come with your own questions. I would familiarize yourself with your essays again, but my best advice is to be yourself. Feel free to message me with any other questions about interview day if they come up!