The TV joins with a code.

Open /present on whatever the room is looking at — the TV's browser, the laptop wired to it, a tablet at the end of the table. Type the six-character code from your console. Connected.

No install. No accounts for your players. Nothing to configure in the ten minutes before a session that was supposed to have started already. Push an image and the room's screen changes.

Pairing is part of Live Play, which is off for new campaigns. Turn it on for the campaign once; after that it's just the code.