The problem you have is not what you stated. The problem is that you're looking for a way to get an HDMI signal that far out.

Your actual problem is how to get a high resolution video signal that far out. HDMI is a 17-wire solution for short distances. SDI, which Brent suggests, is your solution.

I'm always bewildered that people want to move an HDMI signal over distances too long for HDMI transmission, and then they start talking about "HDMI over coax" or some other such thing, instead of making the conceptual switch to thinking about the original signal and asking themselves what TECHNOLOGY will deliver that RESOLUTION at that DISTANCE.

It ain't HDMI. My support for that recommendation is that Brent did not suggest an HDMI solution.