We can make a Dickens Cinematic Universe. Besides Scrooge, each of the three ghosts surely has a story. And what about Marley, the portentous visitor? Surely he's got a story about how he ended up in chains wandering the Earth. Could do a whole afterlife thing where he redeems himself and is freed at the end. And a prequel of his story! What about Scrooge's ex-fiancee? The quest of the urchin to purchase that turkey!