S. causiarum has done very well in Augusta, GA. I have several at the school where I teach and they are about 15' tall with 6' of trunk. S. maritima has been less foliage hardy as has S. domingensis. All the Sabals seem to gain hardiness the longer they're in the ground. S. pumos was hurt when it was young, but seems to be doing well now. I had the same experience with S. rosei and S. mexicana: winter foliage damage as young plants, but they 'grew out of it'.
S. rosei in the middle. This one was bearing seed even at this small size.
S. mexicana in Augusta, GA.
S. causiarum in Augusta: the S. causiarum is dead center sticking up over the palmettos. I'll try to get a better picture.