I don't own a "smart TV." If I did, I would have two options to secure it.

I could keep it disconnected from my home network, except perhaps occasionally to update the firmware. Otherwise, all network content would come from a device in which I could place some level of trust.

Alternately, I could put it behind a Gargoyle router set to push all content through Tor. That would render some network content inaccessible, and Vizio itself might block Tor exit nodes.

Each of these choices introduces inconvenience and reduces function, but right now I would not trust my activity to Vizio, after seeing this financial reporting.