The Sabal minor was of unknown origin so it may have simply been a less hardy ecotype. My other known "McCurtains" performed better, i.e. hardy "as advertised". This particular minor seemed somewhat different from them. It had longer stems on the fronds so it might have been a "Louisiana" or some other big variety... who knows? Maybe even a Sabal palmetto? (I wouldn't kow how to tell at that age). So, at least, I am pleased that my known Sabal minor "McCurtains" are doing well.
I should ad, before I tried "McCurtains", my opinion was that Sabal minors were less leaf-hardy than Needle Palms. I had tried a few at my old house, from unknown seed sources, and any exposed foliage got bleached white by spring! So I couldn't understand what everyone was saying, that Sabal minors were so hardy. But with real "McCurtains" now, they seem as hardy as Needles. So, I think with Sabal minors at least, the origin of the plants really does matter in borderline climates.