This 100′ HDMI cable and splitter combination works: https://www.amazon.com/gp/product/B005LJQNAG/ref=oh_details_o01_s00_i00
https://www.amazon.com/gp/product/B002WPAU38/ref=oh_details_o02_s00_i00
I had bought these for output from the ATEM TVS, but just decided to try them from my cam going into the ATEM TVS. The 100′ cable runs from the camera to the splitter, and a short HDMI cable goes from the splitter to the ATEM TVS. The image quality is the same as if I only used a 6′ HDMI cable.
Carlton