I get an inadequate WiFi signal to the semi-attached garage at my home from my Shaw Ignite WiFi Gateway (Gen 2) modem (XB7).  

It is easy for me to run a cat 6 cable to my garage through an existing conduit... so I was thinking I could just buy a second wifi router. 

Q: Can I add a second wifi router connected to the Ignite wifi Gateway modem.  And, can I use the same wifi network and password as in the main house?