The second part, like the first, was set at 10 episodes, but it seems the special holiday episode is being counted as one of those 10. So, we've got nine more coming to us when the new season kicks off.
Oh, and while we're on the subject, it seems like there's a lot of confusion over what season this is. Apparently, "part two" is actually an extension of season one, and parts three and four technically make up season two. OK, sure.