Well, I am not certain that height even matters a lot in this conversation. A 68" bow is a 68" bow. It works or it doesn't. A lot of us routinely use long bows of 66" and more, even in a tree or from the brush.
I suggest that before you go hunting, you practice from a stand to see how you need to stand to shoot whatever bow you have, and then to be realistic.
You are shooting a bow, it takes room, you will not be able to shoot 360 degrees around you, even if you prune the entire top off the tree.
Pick a bow that you like, shoot it a lot, then shoot it even more from within the brush, so you get a feel for clearances.
Shoot it at an extreme down angle, as if a deer is beneath the tree stand you are hunting from. ( I might suggest you turn your body enough such that the lower limb, when bent at the waist and aiming down, is behind your knees.
ChuckC