@stephgo 

Welcome to the community.

You could check with the following retailer to see whether there is a single P9 available.

https://www.tp-link.com/ca/where-to-buy/

If still not, I think maybe P9 is not sold in a single pack in CA. 

Since all Deco units are compatible with each other. you might consider adding another model, like M3W or M5 to extend the Mesh coverage:

https://www.tp-link.com/ca/home-networking/deco/

Can different Deco models work together?

Thank you very much.

best regards.