Though I try to keep it in the 4 to 5 hour range, I will drive 7 to 12 hours on occasion. Like you, I use night hiking to extend my trail time. I'd say I've night-hiked on 40% of my trips this year.
Now if I could only stop getting lost at night.
I have one hiking buddy who won't go hiking anywhere that is further than 2.5 hours from his house, and refuses to night hike under any circumstance. I just don't understand that type of rigidity. Who said getting out into the piney woods had to be convenient?