With that kind of surface area to cover, and with how higher frequencies are not passing through these kinds of walls easily, you'll have trouble finding a single router that covers it all.

You could try a router that can do a mesh network with a dedicated wireless backhaul to ensure good coverage, but if the walls are impeding the signal too much for the wireless backhaul to operate to a satisfactory speed then you may need to go with a wired backhaul, which is to run Ethernet wires from the main router to the mesh nodes.