@sdwas 

Based on the Wi-Fi demands that you detailed, your bandwidth needs are not that great.

You indicate that there is an Ethernet line to connect the main router to the other end of the house. Which is good, but you don't indicate the construction materials/methods of the interior walls, the number of interior walls separating parts of the home, or the outside sheeting. You also fail to mention the age of the home construction; (which lends some understanding to the construction materials and methods used). 

All of those factors will impact the distance between Mesh nodes using either WiFi or Ethernet back haul. And a better understanding of user device placement is necessary to fully determine how to best cover your home, including the garage in Wi-Fi. 

If you can supply more details on your home, we can get more precise with specific recommendations.  

I always recommend a Deco MESH, as you can add any of the different model notes in to expand the MESH.   

Currently CostCo online, has the Deco M9 Plus AC2200 on sale for $199.99  OR The Deco X60 Wi-Fi 6 AX3000 for $279.99

If you want to enter into this blindly, then I would start with one of those two three node mesh systems.

@DAServices Thanks so much for the response and information.  Our house was constructed in 1937 so many of the walls are plaster over wire lathe, while the newer construction is typical stud and drywall.  There are a total of 4 walls (2 drywall) separating the main router location to where the primary ethernet mesh connection would be placed (~110 feet).  I also have some other options for the mesh placement with an ethernet backhaul with less obstructions/distance that should offer full coverage.

@sdwas 

The year of your home construction tells the story. The Lath and plaster walls are a very efficient Wi-Fi shields. Making it difficult for Wi-Fi signals to penetrate the walls.

EXAMPLE :

In setting up a Deco MESH for a customer in a similarly1945 constructed home, I needed to place a MESH node near the outside walls of nearly every room. The signal penetrated the wood floors from the basement but not the lath & plaster ceilings to the second and third floors. The three mesh nodes on the first floor used the Wi-Fi back haul easily but the second and third floors needed a wired back haul to connect to the primary node in the basement. The detached garage was again an issue due to the metal containing FlagStone exterior. This required a PowerLine 1000 to get a back haul out to the node in the detached garage, to service the patio and pool area. 

Remember the Deco Mesh easily accommodates up to 10 nodes.  You can combine any mix of any Deco node, including but not limited to 3Mw & M5