> Just buy a TV and don't connect it to the Internet.

There are some TVs that eventually pop-up a “please connect” or similar message over any display (even if just using it to display content from another device via HDMI) if they have not been connected for some time, so that you can't permanently use them disconnected. I forget which brand(s)/models are involved, it was talked about in at least one of Louis Rossman's rants so you might find some details in the consumer rights wiki he is associated with.

There will be ways around this of course, though they might involve mucking about in a way the average TV user will not want to risk playing aroud with (rooting the device so you can alter an internal clock that is not affected by any clock you can modify on the UI, or pulling a battery backup out so everything resets (assuming the clock's state is not stored in solid state memory than needs no powered at all to maintain)).