Choose one unit for a known central location
A single unit is sensible when the modem enters near the center, the space is compact, and one current router already reaches most rooms. It avoids an unnecessary wireless backhaul hop and leaves budget for a switch or cable run.
Choose two when the layout creates a real relay job
A second node helps when another floor, long hallway, thick wall, or off-center service entry creates a repeatable weak zone. Place it where it still receives a strong link, not inside the dead zone it is meant to repair.
Wired backhaul changes the decision
Ethernet lets the second node serve a distant room without spending wireless airtime on the inter-node link. Confirm the wall run, switch, and port speeds before paying for a premium backhaul path.
Do not buy square footage alone
Coverage claims cannot describe brick, concrete, metal, neighboring networks, furniture, or vertical layout. Use the current signal map and the return window as part of the node-count decision.