I've seen a few of the pesky little
trees with diameters of 1/2" or less at a few feet high - it's possible.
I sure like moving
trees in fall. Never lost one doing that. Of course, I don't think I've ever lost a transplant ever.
Even got a 25 foot tall weeping giant sequoia free from the dept. head of the college program I attended - moved it in June in 85 degree weather. It was in the shade in the woods, with a tap root through it's huge pot. I had to tip the pot to cut the root.
Moved the
tree bare root, sprayed to seal it, wrapped like a mummy with the roots on the tailgate, trunk on the cab, and the canopy resting on a huge X strapped to the bumper - it looked wierd !!
We erected it in a hole, filled it with water and sloshed soil in to make a mud soup to squish contact with roots. drilled and anchored eyes in the trunk to brace 3 directions. After many more hot days, the summer, fall, winter,
spring, it still lived on.