Google suggests, for an earlier version TV, that this is a weak power supply in the TV, or a weak power feed. I have the TV plugged into a multi outlet surge suppressor. I changed the outlet for the TV yesterday. I think it highly unlikely that the power cord itself is the problem. I have not had the reboot symptom since.
I will continue to monitor this....
Also last night the wi-fi issue came back but there were local reports of internet access issues so I rebooted the router, just ot be sure, and all was well. Internet this morning is fine so we'll see tonight how this plays out.
Fractal Design R5 | Asus Z170 Pro | Intel i5 6600k | 16 GB G.Skill Ripjaws DDR4 2133 | Seasonic 650w PSU | eVGA GTX 550 TI | Samsung 960 M2 500 GB | Samsung 850 EVO 500 GB | ASUS Burner | Windows 7 64-bit