You're going to have to pull new cable. To be completely safe at that distance, I'd consider the Celerity HDMI/Fiber solution. The good thing is the cable is very small and easy to pull.New member in the problematic HDMI cables camp.
After I got my Xbox One S to send the HDR/WCG signals to the PJ it became apparent that my cables can't hold these signals in a stable manner. I have two 10m HDMI cables running from my processor to the PJ, and each of them can hold 1.4a wihout issues (including in 4K resolution), but nether of them can pass stable 2.0.
Is ther a way to make the two cables work in parallel (by utilizing 2 outputus of the receiver and 2 inputs of the PJ), or may be there is a splitter/merger device that can send signal over 2 parallel cables?
The cables are built into the walls, and it would suck if have to reinstall a new cable.