[dianebrat]

As the unofficial Powerline cheerleader I see nothing wrong with your plan.
I've gone one step further, my FiOS line comes from the ONT and hits the wired only router in the basement that has a powerline and M0CA connections, and the wireless AP is in the living room at the center of the house is fed by a Roamio in MoCA bridge mode and it works flawlessly.

 

[dianebrat]

Powerline is a crapshoot, just like wireless. Can work great one day and not the next depending on your house wiring and local interference.

Better make sure you can return all that $375 worth of stuff if needed, or pay someone to run some cables instead.

I have never seen that kind of issue in powerline unless your house wiring is crap, on a reasonable 3 wire grounded system wired to code it's almost always solid, and IME far more stable and less prone to interference than any wireless protocol I've used.