Originally Posted by palmtree

Red Abynssinan bananas are botanically called Ensete ventricosum "Maurelli". Maurelli is the cultivator name. Normal Ensete Ventricosum bananas have green leaves only.
No matter how cold tolerant a banana is, most of them have damaged leaves at about the same temperature. Some of the thicker leafed varieties can handle more frost than the thin ones. Ironically in my experience Musa Basjoos get frost damaged faster than my tropical banana plants even though its a hardy banana that comes up every spring from the ground around here.
I think for cold tolerance the Ensete will be a better choice. They are more vigorous than Siam Ruby bananas. But the Ensete will only live maybe 3-4 years before they flower and die. And they do not pup (well they can but the process is kind of complicated and not really worth it IMO). Siam Rubies are great bananas and they are puppers so you will not have to replace them. They will get damaged by frost (probably faster than Ensete) and they dont get to be as massive as Ensetes, but they are really nice short banana plants that can get pretty nice sized with age.

Ensetes are hardier than Siam Rubys but they both will survive in a zone 10b (and only temperatures in the low 30s or colder will make the leaves look really ugly).

Good luck! Maybe you sould try both Ensete's and Siam Rubys and see which one is your favorite!