As Bob noted, they're most dependent on cultivar, really, and of course other factors.
Great examples: Rajapuri: Grows only 6-7 feet tall avg, but the trunk can get to be bigger around than Ice Cream, which can grow 18 feet tall. My Yunnan gigantea can get to be about 25-30 feet tall, yet be much smaller in diameter than the Ice Cream. Also, look at your mean temperature for your microclimate. You can buy an inexpensive digital thermometer which can read your mean temp, which can give you an idea of just how much growing time the banana will have outdoors in the location you choose for it. Remember that bananas pretty much halt growing below 70 degrees and above 90-95 F. Have you ever tried Grow More "Banana Fuel"? I dont really have a need for it in my region, but I've heard great things about it, and should help boost your growth in a shorter season region.
