If you don’t connect the LG to the network it can be just a dumb monitor. Set the tv to always use the last active input when you turn it on and you will never see a menu or any prompts.

I would first have a conversation to find out if selling is something they’d be open to. If they aren’t interested in selling, you might see if they’d be open to doing a deal where you pay them a fee for right of first refusal. That way if they ever do decide they want to sell, you will get first crack at it.