This my update for the past couple of nights, since they were both pretty much the same. I turned in at a reasonable time of around 12:45, and I woke up in the early hours to attempt a WBTB, but with no luck - I fell asleep both times. I think I need to wake myself up more during WBTB sessions, since they only ever succeed on those nights where I think I'm not going to be able to fall asleep again.