Yeah, so my kids have lost the remote to the Apple TV so many times that it has become a thing.  At one point, we even purchased a new one, since it was weeks without locating the remove.  For sanity sake, we figured we need to put a tracker on the remote so that WHEN the remote id lost, we can locate it easier.  I found a basic ATV remote case and then used Blender to add a key ring to it.  Nothing fancy, it just works.