Ice cream is growing in the test plot at Bamboo Farm and Coastal Gardens near Savannah, GA. I would say they get about 5 degrees colder than we do here. Even though I am a little farther North, I am closer to the ocean.
I picked up one there during their Fall Festival, when they sell pups. I also brought one I believed they called Dwarf Nanwah and one for Stan called Kandarian. I believe they all 3 bear fruit there and were highly recommended by the professor that runs the banana trials. I know Kandarian overwintered last winter and grew to 25' tall.
Here is a picture of Kandarian taken in the Spring of 2007. It was even taller last month.
http://www.bamboo.caes.uga.edu/
Ned