Dang...jrparbor04. Your suggestion goes against all the documented information on transplanting Liriodendron tulipifera that I have read. All that I've looked at recently says "spring". My experience says don't guess at it. Research it!
I have researched it and I have practiced it. The large tree pictured was about 2' tall, in full leaf, dug out of the woods and transplanted in mid-summer. It didn't skip a beat. Once again, you must put the water to it until reestablished. An adequate mulching is also required.
"Tuliptree is extremely sensitive to being transplanted in the Autumn (a general characteristic of fleshy-rooted and coarsely-rooted woody plants), and extra care should be taken to amend the soil, fertilize, water thoroughly, mulch adequately, and avoid Winter salt spray, to enhance survival chances during the first Winter, if transplanting cannot be delayed until Spring"
http://hcs.osu.edu/pocketgardener/source/description/li_ifera.html
"Trees can be planted from containers at any time in the south but transplanting from a field nursery should be done in spring, followed by faithful watering."
http://edis.ifas.ufl.edu/ST363
"Planting Notes:
Difficult to transplant. Once established, it is a fast growing tree. Move young plants with balled and burlapped roots in the spring. Plant in a location where it will have plenty of room to develop. Select a site with fertile, deep, moist soil."
http://www.treehelp.com/trees/tuliptree/index.asp
"Any transplanting is best done in May[11]."
http://www.pfaf.org/database/plants.php?Liriodendron+tulipifera