I found that NIK did a good job but is aggressive. I did not take the time to learn how to use it manually. I just just use LR or ACR now. First off the 7D2 is a light hungry sensor. A correct exposure and even a little to the right is paramount for this camera.
I would just apply what I learned in LR to NIK and adjust to taste.
My 7D (not 2) at 12,800
No NR. I turned the default of 25 to zero.
Apply colour noise until the blochies go away. Once done stop. Going any further does not accomplish anything and actually starts to change hue.
Then apply luminance to taste.
Final product

























