You may want to try-before-you-buy, by placing an ordinary WiFi router in different locations, and using a cellphone app like “WiFi Analyzer” to see what kind of signal levels you get. (You don’t need ISP connectivity, the router will still broadcast without it. . .)
Depending on the dimensions of your rooms, an access point in the hallway by the door to bathroom 2 might be able to cover both bedrooms on its own, leaving the AT & T router (if it has WiFi) to cover the living room/dining room.
You may want to try-before-you-buy, by placing an ordinary WiFi router in different locations, and using a cellphone app like “WiFi Analyzer” to see what kind of signal levels you get. (You don’t need ISP connectivity, the router will still broadcast without it. . .)
Depending on the dimensions of your rooms, an access point in the hallway by the door to bathroom 2 might be able to cover both bedrooms on its own, leaving the AT & T router (if it has WiFi) to cover the living room/dining room.