This room 75 ft away, what is in between that room and the router? Walls, doors and such? Stuff like this can effect signal travel and quality. Can you place the router closer to this room. Centralized placement is recommended if possible. However if your at one end of a building and you have to get to the other, extenders or relay devices are probably better off or you can add a 2nd wireless router and make it an access point, however you'll have a different SSID. Extenders or relays have the ability to just tie into the main SSID broadcast so you still maintain the one and only SSID.