Longer cable runs between a source and display, the latter usually a projector, are a hot topic in the custom install business and in DIY installs as well. HDMI can’t usually handle much over 25 feet of UHD over HDMI, and even that’s iffy.
If Ethernet conversion isn’t your thing, nor are fiber optics (another work-around on the traditional weaknesses of HDMI over long lengths), a few companies are now offering either passive or a combination of passive/active HDMI cables that can extend far enough for the needs of most consumers.