Answer: A squishy trunk sounds ominous. It may have root rot, in which case it won't return this spring. Give it another couple of weeks to sprout. If you see nothing, dig it up and look and the roots. Squishy roots are not a good sign so if that's what you find, toss it out and replace it with a healthy new plant.
You should be able to find banana plants at any local garden center. Sometimes they're kept in the indoor plant section so look there, too. Or, phone your local nurseries and garden centers. If they don't stock the plants they may be able to special order one for you.
Best wishes with your garden!
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