Sabal palmetto... not likely to survive without protection. Your best bets are sabal minor and rhapidophyllum hystrix. With sabal minor, you want either the McCurtain variety, or another hardy variety from Arkansas or North Carolina. If you are going to get sabal palmetto anyways, get some seeds from the North Carolina ecotype if you can.

Try sabal minor 'Hatteras'. When I lived in Maryland I had bad luck with 2 different 'McCurtain' varieties of sabal minor. But Hatteras did pretty well. Probably related to winter dampness and wind. Also find the best microclimates in your yard such as against a southern wall, under a canopy, etc. Good luck!