While this is not an officially supported configuration, we have tested this successfully in our lab environment and did not have any trouble using this.
Here is what this was tested using:
1x Set of J-Tech Digital HDMI CAT 6 Extenders
1x Spool of J-Tech 150ft Cat6 UTP Cable
2x Basic HDMI Cables
This was essentially plug and play with zero configuration or special knowledge needed. You just connect the receiver end via HDMI to the display, and the transmitter end via HDMI to the Screenly player. Once done, connect the CAT 6 cable between them and power them up.