Hi
@cameranoobie, there is different roads leading to Rome. Like
@TonyR suggested: the easy way is to connect your wifi cams to your (internet) router, you make a powerline connection from the NVR (P2P to say) to a powerline outlet close to your router, and plugin that ethernet into the router. The NVR will then "record" and "analyse" the streams coming from the cameras, over the router, into the powerline and terminating in your NVR. But powerlines tend to be "situational stubborn", meaning that even a device certified as gigabit, can be a pain in the **s because of: - your wiring goes twice around the house, - induction from external radio signals, - fuses giving resonance in the signals, - or just because they can.
Another way of looking at a potential setup (in my opinion a bit more "nice" in point of view of security, as the cams are "separated" from your home wifi): depending on your NVR (having a DHCP on board on POE camera ports or not): you could install a "simple" access point, on which your cams connect to. You'll only need a powerline uplink (which will only be used when you actually view NVR/camera footage). It will for sure guarantee a "certified" uplink from the cams to the NVR.
All depends on how simple/sophisticated you want your setup to be, but also depends on your $$

Choices choices

I like your idea of "hiding" all cables, but in the end, your NVR needs power too (are you making an electrical outlet in a closet)? Then you'll quickly face other challenges, as NVRs get hot. And you'll need ventilation. Another thing to think about: I prefer my NVR to be up&running 24/7. Even with powerloss. So drag in a UPS too (or put that NVR electrical outlet on a protected UPS circuit). So again, choices choices

If it is because you want NVR footage with HDMI to a TV on top of a closet, I can advice HDMI over UTP extenders, so you can hide your NVR somewhere really hidden

Good luck!
CC