I can understand why you’d want to do that—watching TV outside on a nice evening is great, but outdoor TVs from company’s like Sunbrite can be expensive. You write that the TV will be covered by a patio roof, but it’s otherwise exposed. About a week ago we had driving rain that was nearly horizontal. If you live in Memphis, I’m sure you’ve experienced the same thing. It doesn’t take much water to destroy a TV. Even if the TV doesn’t get a direct hit, it gets pretty humid there, and extreme humidity can be very unfriendly to the insides of your TV. Finally, there’s insects. I heard about a TV that was infested with hornets, and the bug spray to kill the hornets also killed the TV. Any little opening on the TV is an invitation to spiders and bees and other nesting crawlers.
TVs designed for use outdoors are designed to withstand all those things, which is why they cost more. There’s a bar near my house that installed a standard TV on the (covered) roof deck. The owner thought he was saving money, but he’s had to replace the TV three times.