Hi Bob,
Yes, the Grand Tour lowland does have some areas with traffic signals (what you call "stop lights"), but these are well balanced by lots of miles without forced stops. If you start at first daylight and keep a 16 mph average, you would have no trouble finishing before dusk.
Of course, you would have to spend minimum times at checkpoints, and ride an intelligent double, but all things considered, it should be quite do-able!
Remember too, that Kermit schedules the Grand Tour for weekend with the most daylight here in SoCal.
Best Regs,
Rick / OCRR