I did this on an outdoor TV where the length just was to long for the single extender we had.

We had a junction in the garage about halfway, so ymmv. But we installed 2 extenders and connected them together. Powered the first from the transmitter side and the second from the TV side. Used an in wall box from snap to put it all in.

Probably not the most elegant solution, but it's been sitting fine for over a year now. It's what we had on hand and we made it work. Sources are a dtv client and apple tv. Snap HDMI switcher between.