LG (at least for my OLED model) supports firmware updates over USB, and posts firmware updates to their website. It's a very smooth flow -- my years-old TV has never had an internet connection and is up-to-date.

Thank you, and babypuncher, for this advice! I avoid using the tvos but dislike how a parade of web connected ads pop up if I hit the dashboard button by accident. Glad I can airgap it again.

Most, if not all, routers have a one click blacklist device option. Pretty easy to just unblock it once a month and check for updates?

Alternatively, for something more automated, you could just use parental control 'bedtime'. I use it currently to keep the kid from watching TV at certain hours. Could probably do the inverse and block it except for an hour on a particular day, I'd imagine.

You can update the firmware on LG TVs with a USB drive, no internet required.

"Why you got such a bent nose, Muggs McGee?", asked Jimmy.

As Jimmy waited for a reply, as Muggs turned beet red, he again noticed how that poor nose was bent, deformed even, and did the man no favour.

Muggs, anger at a peak, spat out "Twas the babypuncher, Jimmy, the babypuncher. He got me as a babe"