I stayed with Hogwarts until the end of February but didn't quite manage to finish the ten hours. But I have now! I've started on the actual picture and progress has been quickened by the background being mostly made up of half stitches.
Here's where I left off:
And the full piece:
If you look closely about 1/3rd in from the left at the bottom there's a small triangle of bluey-grey - that's the castle turret beginning to appear!
According to my calculations, I'm just under a quarter of the way through. This might be a little bit of an overestimate but has made me think that maybe it's time to put in some of the backstitching. So that's the first thing I'll do when I return to it.