So far all the Roku TVs I’ve tried will let you skip setting up Internet on them and then default to a dumbed down mode where the Homescreen is just TV inputs, and you can access the settings menu. Haven’t had a chance to test a recent Android/Google TV.
Update: Seems Sony, TCL, and maybe some other Android/Google TV makers allow using the TV without linking a Google Account.
https://www.sony.com/electronics/support/articles/00115361
https://support.tcl.com/can-i-just-use-basic-tv-on-a-tcl-google-tv
Update 2: Samsung seems to let you skip logging into their TVs during setup via a Skip button in the top-right corner, but it’s unclear if you can skip connecting to the Internet at all.