If its really that far in, you should be ok with leaving it there and not having someone discover it (of course, that's always a risk).
I would set the climber up the afternoon before, take it up and down the tree to make sure all is fine and then just leave it there over night. Might want to take some camoflauged burlap to help better hide it in case someone else stumbles through the area.
Also, I'd suggest putting something over it so you can find it in the middle of the night. I'm a big fan of reflective thumb tacks
If it were me, I'd hike in well before dawn and climb up in the tree. Your bound to make noise and get a little sweaty, best to let the forest calm down as much as possible afterward.