Yes, in the Kölner Flora (Botanical Garden of Cologne) there are some old corms surviving the winters protected like Musa basjoo. The microclimate there is favourable and so that Musa basjoo and balbisana are surviving there, see also my page
http://www.basjoo.de.vu, if you do understand German.
Only provenances from the coldest mountain areas might be hardier and suitable to try in Germany, but only older plants with firm and large and some woody corms and pups could survive outdoors protected like Musa basjoo.
Best wishes
Basjoofriend