Cut the cable, what now for the coax?

[Angrboda]

The Firestick in the living room seems to be uncertain about the current connectivity establishment. That set is as far from the router as you can get here and still be indoors. If that doesn't resolve I want to up the game.

ISTR something about a Fire device with a better WiFi antenna than the standard Fire stick. I might be misremembering something, and even a better antenna might be marginal if it's far away from your router, but it might be another option to consider. There are also WiFi extenders, but those probably cost just as much, and from what I know of the one device that I've looked at, they may halve your bandwidth at each step. Still, half the standard WiFi bandwidth is probably plenty for a Fire stick.