USDA zones just dont work at this latitude.
see map of climate zones
File:India climatic zone map en.svg - Wikipedia, the free encyclopedia
plants from the Eastern Highlands moist deciduous forests, the Himalayan subtropical broadleaf forests North Western Ghats moist deciduous forests are all possible candidates for european and US (non florida) growers.
Pahari Kela from Uttaranchal Pradesh and Hajaray from around Kalimpong West Bengal
may grow with protection in USDA zones 7/8. i guess it's a matter of trying these things.
I doubt if there is a hardier banana than Basjoo, but it may be possible to find a cultivar that will produce edible fruit. Only one way to find out.
I was aware the Dhusray and Malbhog but not Hajaray had been exported from India before. Anyone with info on Dhusray and Malbhog growing outside of India?