This rarely works. The TV network is usually access controlled, so you either won't get an IP or you simply won't have internet access.

Some hotel rooms (particularly older business hotels) will have an ethernet port for the guest. These work maybe 50% of the time these days. Sometimes you can find a Ruckus AP in your room at outlet level, and these usually have several ethernet ports on the bottom. These also have a working port around 30% of the time.

So, TL;DR: various ethernet ports in hotel rooms work less than half the time these days.