Per
@OzarkEdge's advice, I'd try to find a high/centralized place to put the wireless router, if you can, to keep your setup as simple as possible. Perhaps high atop a kitchen cabinet, mostly hidden? If that's at all possible, I would go that route first. Explore
all options
.
If that just won't work, then yes, most likely you're going to want a second broadcast location in or near the bedroom, ideally connected
by wire to the main router (by ethernet or
MoCa over TV coaxial) for max reliability. Ethernet is of course the best choice. Second would be MoCa; you'll need
MoCa-compatible splitters at all points along the cable path, plus at least two
MoCa 2.5 adapters. Lastly, I would avoid powerline adapters altogether; operational certainty is too low, on average (it may work; it may not; it may start out working, then degrade at random or all at once, or only when the blow dryer is plugged in, or when the dishwasher runs, etc...).
As for wireless hardware, a cheap, standalone AP, extender or all-in-one running in AP mode may be simplest. If your main router is an AiMesh-compatible Asus model, then another AiMesh-capable Asus would allow for a bit easier management of both. For a good chance of even more seamless client roaming and set-and-forget reliability, I would either 1) disable wifi on the router and put in a pair of controller-based APs, such as Cisco
CBW140AC's (~$110 ea) (plus two $16
PoE injectors to power them), or if that sounds too complex or spendy, 2) simply replace the router altogether with a hardwire-capable consumer mesh system, such as Eero (
dual-band 3-pack for $175).
Hope that helps. Any questions, feel free.