Looks you have a coverage concern,
All Access point have a coverage limit (called also coverage cell) that may vary from environment to another,
if you need to cover more areas in your environment I think you will need to add more APs, and if you have a lack of cabling around your home, you can run you instant APs on a mesh fashion,
check out this article, it talks about mesh deployment:
https://community.arubainstanton.com/t5/Blogs/Is-Mesh-Wi-Fi-Worth-It/ba-p/781