I would also stack 3-4 tiers (depending on the size and how heavy it will be) then add the last 1-2 when you set up at the venue. For the tree design you can split the tree where the tiers will be split (make sure it will line up when you stack it!) and hide the seam with a branch, leaves, flowers, etc.
Goodluck!
Nikki, So Cal, www.Facebook.com/nikkibelleperchecakes
