I recently picked up a Heller's Holly at the local nursey. The tree is in pretty good condition. However, it looked like it had been left dry a couple of times. The soil looked like it had pulled away from the sides of the pot at one time. I've submerged it for 20 minutes and that helped. It also is fairly rootbound, I've seen worse. My question is, can I transport it into a larger pot to give the roots some room? (no root pruning, just adding extra soil) I know it's out of season to repot but would this be considered a repot, stress-wise, to the tree? Please advise...