The lucid dreams returned yesterday morning at sometime between eight and ten. I woke up at seven to start the day, showered, dressed, and - for whatever reason - felt compelled to nap for an hour (during which I was able to come in and out of the lucid dream state and fly/float/melt around the room.)
After such a long gap, I think part of the reason the dreams returned involves me getting back to a consistent sleep schedule.