Yup. I did this with my Vizio TV and it worked great for a while. Then the TV started rebooting mutiple times a day. If i disconnect it from the WiFi or let it have full internet access the problem stops. It seems that their "Smartcast" app will crash and force a reboot if it can't phone home when it wants.

I paid good money for this TV back when Vizio wss considered a good brand and I hate to retire it just for this, so I've given up my nice Home Assistant integrations and it's just a disconnected dumb TV now. You can't downgeade the firmware either so they've essentially killed the smart features for me. Should be illegal.