Wifi Extender for Apple TV?

We are trying to figure out how we can make the best use out of our tv in a room that we don't frequent that often. We used to have basic Comcast service connected to it, but discontinued it because it was used once or twice a year and not worth the monthly fee. Any room DVR doesn't interest me either. So I came to the conclusion that just having a stronger wifi signal to that room would allow for Apple TV to work, and then we could just mirror whatever was on our iPads. So we went to Best Buy to find out our options. Because I didn't know what make of modem we had, or know enough about wifi extenders, and they didn't have the new Apple TV version, we left. We just had Best Buy set up a new LG Oled tv a few months ago with Apple TV. I'm thinking we may just call the tech back and ask him what we specifically need to do. I'm not even sure this idea will work. If nothing else we do need an extender just so the wifi signal is strong. Having the Apple TV option would be a bonus. I just wish I knew more about this stuff. Or maybe we don't do anything at all.