I know the feeling. I got new irons the other night and ran over to the range, but the floodlights they have only light up the hitting area. The light that spills over into the range is enough to see out to 100 yards or so clearly, but beyond that, the balls disappear into the night. It doesn't help when your main goal is trying to gauge distances for your new irons.
But the glass-half-full side of me remembers that I was able to go to the range at 9pm the night before a round, so at least that was better than the alternative of not practicing with them at all.
My conclusion is that if that range is your only option, then yeah, its worth it to get swing practice. But if you can go somewhere else, or maybe go there at off times, you be better off.