David, I can tell you that my gingers out in the garden pretty much die back to the ground each winter. Here in FL winter is the "dry" season, and we do get nights consistently down into the 50's through November to February, and after a cold front it can get down into the 40's, rarely 30's. If we're going to have a run of cold nights I do dump some extra mulch on top of the rhizomes.
If you can sort of simulate those conditions, I'm sure they would do fine through the winter. Cool temperatures, relatively dry although they don't dry out completely because they do get a little rain, and as long as the nights are cool they don't want to jump up and grow.
If you want to get blooms next summer, I would pot them up and bring them to your warmest, sunny window sometime around March or so. Then get them outside as soon as the night temperatures are warm enough, . . . say for you to sleep with the windows open. Most of my gingers don't need full sun, but they do need warmth to bloom.
