Not that you asked, but it may interest you to know that the
least hardy is heliconia (indica?) 'rubricaulis'. It is a cultivar collected from the South Sea islands over a hundred years ago. See
If You Like A Real Challenge
When I was a teenager, circa 1960, Garfield Park Conservatory in Chicago had about 5 large clumps growing in their fern room. See
https://www.google.com/search?q=Garf...w=1280&bih=635
One winter day, I walked in and all of the H. rubricaulis looked like an elephant sat on them. They never recovered. I asked what happened and was told that there was a heater failure that caused the air temperature to dip to 45 deg. F. during the night. They were the only plants affected.