Every few years the US Department of Agriculture revises their Plant Hardiness Zone maps. The maps are an invaluable resource to gardeners and nurseries, and are a reliable guide for understanding what plants are able to overwinter in a particular area of the country. Its folly to attempt to create a garden of plants that won't thrive in your neighborhood. The maps are revised, and provide anecdotal evidence to non-believers, that winter temperatures in the US are on the rise.
When I began gardening in the early 90's all of Missouri was situated in USDA Zone 5, which meant that winter low temperatures would hit -10 degree Fahrenheit (-23 C). Today, the same garden sits in Zone 6, with winter low temps 5-10 degree warmer. Since the 1990's map, zone changes have inched northwards 10 miles per year.
I have always wanted a southern garden but I like it here and and am unwilling to move. However, if the current rate of change continues, the Fashionista can spend her dotage with a New Orleans garden without having to leave home.