Update:

Woke up yesterday at 6:43 a.m. -- *wide* awake -- after having slept maybe 6 1/2 hours. Tried very hard to go back to sleep, but gave up after 30 minutes. Weird.

Last night was a little closer to "normal". Went to bed shortly after midnight, fell asleep around 1:00, and then woke up this morning between 8:30 & 8:45. Hopefully this will continue.