Didn't get a whole lot done today after all. I got a bit too engrossed in a fantasy novel I enjoyed in my teenage years and recently rediscovered.
So having read a four-part series in no time flat I got to work doing what I should really have been doing this morning. It was actually easy enough to cut the hole through the ceiling. I had to move it slightly - the dead center of the room was within a fraction of an inch of a joist supporting the attic and I needed space to put a light fitting in there, so I moved it a couple of inches. That was enough to mean the ugly hole I made when I pushed the wire through the ceiling still shows - I'd hoped to have been able to cut the circular hole such that it was cut away but it became obvious that wasn't going to happen. No big deal - it's a temporary measure because the whole of the ceiling is coming down anyway.
Now I've got the back box for the light screwed into place with one of the knockouts knocked out, a strip of fiberglass over the top of it to keep the cold air from the attic from getting in, and a good idea of where to go with it tomorrow. I need to get a power cable into the box, cut a hole in the wall for a light switch, fit the switch and a switch loop, and then I'll finally have a central light in that room. Which will be nice, it's rather tedious trying to work in there by the light of a battery powered work light and a couple of table lamps.
Once that's all done the next step is to get the dust sheets off, have a final clean up, and return the room to a place where it's functional, if not ideal. I'm hoping I can get that done by close of play Friday, maybe tomorrow if things go my way.