You might have missed this, but padcon exists, which allows you to turn off the screen on the gamepad. It saves battery life. A lot!We can't get a second gamepad either, as (according to the Internet) most games don't support it and it drops frames to 30 FPS. It would have been a good option, if we could just turn off their screens (I generally don't use the gamepad screen with MK8).
https://apps.fortheusers.org/wiiu/Padcon