SUCCESS, thanks all! Plugged it in, and all worked perfectly!
The only anomaly is that the Internet "Globe" remains red (which I think is an indication of "No Internet"). But after a little consternation, I verified the internet by connecting to the SSID and disabling mobile data on my phone. We then plugged in the TV via ethernet and, despite Samsung idiosyncrasies, we were able to get that connected up.
The irony is that, although not really strong, the original existing wifi signal from the "main" router out in his detached office would have been sufficient to get the TV set up had I not believed the message, which said the internet signal was too unstable to download the Ts & Cs agreement. We got the same response even when hardwired to the "new" access point, and a bunch of googling later found out there was another path to accept the agreement and that worked just fine.
Oh well, maybe I will eventually convince him to learn how to navigate netflix, hulu, and youtube!!