Part of the exercises we did for my security guard carry permit class, was shooting in low and very low light.
In the low light drill, all the lights in the range were turned off except the very last ones out at 50yds. When you'd shoot, the holes glowed in the target as the additional light came through. That was very revealing about point and shoot accuracy...
For the very low light, all those lights were off and all we had was the light coming in from behind us in the other room outside the range. It was pretty dark doing that. The remarkable bit learned from that portion was that our groups were pretty close to those of the low light, and many were better than with full lighting!
I wasn't using night sights back then.
If anyone manages to get a range to themselves, you might see if they're willing to let you do this stuff.