Floor above? It's not a house? I'm sure there's a way to route a cable through...
If you're not gonna do that to play a game you want to play, it's not really the game's fault...
You say your connection is bad but WiFi is always bad...so you could have a wired connection to the internet but you're not putting in the effort for it because...it's easier to just say you have bad internet?... Eh? Come on, don't be like that.
There are 3rd-party routers with stronger signal transmission you could get instead, but a cable is the cheaper and more stable option.