Hmm... The sycamore is a tree which can grow to be over 30 meters tall. How tall that particulair sycamore will grow, i am not sure, and if you cut it down... Perhaps you will know if you are a scientist. Theres probobly some math to calculate the max hight of that tree. But to you and me, prolly not. We wont know :C
If theres an air-pocket where you are... Yes? I mean.. Its not possible to live for even a minute without protection in space. And I don't think you'll die trying to whistle.. ><