[infinity85]

Great work, I really appreciate your instructions and detailed analysis. I will test this setup when I get the opportunity. I never use the USB ports so keeping voltage low shouldn't be a problem. The 5 minute shut off for the RemotePi board should work fine for me better then not at all.

Well...Even without any USB drive etc a jumper wire would be too thin I guess. At least there are two of the 5V and ground connections, but still I would be careful :/. Yesterday Matt (msldigital developer) and I found out why the automatic power cut off does not work. The odroid somehow does not lower the GPIO pins 3.3V output after shutdown, it simply stays high at 3.3V. Though, the RemotePi board waits for the voltage to lower itself to 0V after shutdown (thats how the Raspberry Pi behave...it also saves power and is absolutely logic). But as this does not happen, the RemotePi does not cut off the power and waits for ~5 min (may be 3 min... I didn't count it) and then it finally does it. I've had a look at the option of firmware configuration tool and there is no setting for this timeout unfortunately. But Matt said he'll think about a solution. So may be he'll have an idea in the future for this . Meanwhile you'll have to live with the timeout.

Besides this:
The RemotePi Board does have an IR sensor as does the Odroid C2 have one. Out of logic I think that controlling of LibreELEC does work directly via the Odroid IR sensor. The RemotePi sensor is then only used for the power-on-off signals. But as the result is the same (same responsiveness). this is just a side note.