I felt that part of the problem is size. 1yr Chiquita Gran Nain completely disappeared, when overwintered, outdoors, in zone 9. 2-3yr Chiquitas and Plantains died to the ground, in unprotected spots, but grew back, bigger. I think a sufficiently-large tree could survive in a wind-sheltered spot.
In zone 9, my more-tender, tropical stuff will survive at about the circumference of a man's wrist, mainly taking minor damage at the outer edge of the crown.
I assume that is taking a risk, of a once-in-a-decade temperature drop, and I would be mulching like crazy, or moving things indoors, if that was in the forecast.
(I'm a hefty powerlifter, but my back was sore for a week, the last time, that happened.)