TIL that one of our TCL TV's is wifi-only; of course, it has to be the one that's in the room with the worst wifi reception.
It has USB and HDMI ports, and I've seen mixed results about people using USB or HDMI adapters to connect TV's without a built-in ethernet to the router, but haven't found anything specific to Roku TV's. In fact, some adapters I've seen specifically say that they DON'T work with Roku.
Is there really no compatible solution for this? Moving that TV closer to the router isn't an option.