Ditch the repeaters. Unless you have a mansion, or a bunker, that sounds like the effect of WiFi congestion rather than distance. Repeaters mean that each packet has to hit the air twice, or more, increasing congestion. Deploy multiple APs around the house, and run ethernet cabling to them from the ISP’s router. Configure all the APs with the same SSID, and security settings, and client devices can roam freely between them.