I checked the wiring harness in the headlight area. No damage. Wasn't able to get it to fail while the engine was running. In fact, the harness was almost hard as rock.

I did find two possible culprits though...

1. Both battery terminals had a thin film of corrosion at the mating surfaces.
... Cleaned and tightened.

2. Replaced my stereo (Christmas present! Click here to see!)
...Cleaned up wiring. Moved head unit to lower position where the CD changer used to be. Mounted iPhones (x2) to top location.
Found exposed hot wire dangling!
Removed during re-wire.

Issue has not returned...
To be continued.
Thank you for all assistance!