I've tried to scare deer away from up in the tree with a light..... They just watched like a deer in the headlights. When my feet touched the ground they bolted. Younger does....im sure a smart older deer would maybe act different?...
I use a headlamp if I decide to climb. Green is my flavor. My woods are really thick and it's next to impossible to move quietly in the dark. Most times if i arrive before daylight I'll find a place I can hide and wait on the day on the ground so I pick the "best" tree.... To be honest with u guys I usually wait at the truck until I can start to see a little bit. Ive scared away lots of deers while trying to navigate in the dark. Based on the sounds I'm hearing they jump up, trot 30yds, and stop and wait for me to keep moving. If I linger they move off. That same situation at gray light may offer me a shot vs no shot what's so ever in the dark.
The distance traveled plays a big role and mode of transportation....ideally I want to be at or withing 50-100yds of the destination location at gray light.
I used to get stressed about not being set up half hour, hour, whatever amount of time, before sun up. I don't stress it at all anymore. I get there when I get there.....and the mornings I do make it up all super early I'm bored outta my mind by 8:30 and if I havent seen or heard anything to make me think otherwise I'm packing up so I can go walk around and find something better