I am in Wichita, Kansas and have 4 needle palms that have been in the ground for 3 summers and two winters sans any protection. They have survived quite well. I also have 3 trachy's two of which I didn't protect and they have survived as well. My big trachy I put a lean to tarp over to keep water out of the crown and it burned back but has come back nice this summer. I also have a saw palmetto that has also survived unprotected although it is a slow grower.
My robusta's I plant in the ground and dig up for the winter and my biggest one is around 6'.
I would say for my area the needles perform the best with hardly any browning of the fronds and they actually grow during the winter.