Datavideo CB-62 HDMI Active Optical Cable, 100m

Copper HDMI gives up long before 100 metres. The CB-62 is an active optical cable with standard HDMI type A plugs on both ends, so it drops into an existing chain but carries 4K at 60Hz the full length of the run.

The physical specification is what makes it usable in a building: 3.0 x 5.0 mm overall and a 20mm bend radius, so it pulls through conduit and turns corners that a thick copper HDMI cannot. It works from 0 to 55 C and stores from -20 to 80 C. Note that active optical cables are directional, so observe the source and display markings at each end.