I am new to the sight so excuse my ignorance. I am currently building a cabin in North Georgia, Zone 4. I currently have the 1st floor completely framed.It got cold here in the southwest last few weeks so I wrapped the 1st floor studs with plastic sheathing just to knock the wind off a little. My question? Do I need to remove the plastic sheathing before iinstalling my Zip6 on exterior studs? Or would it be OK to leave it.

southeast, not southwest

Remove it....from history learned by others the air/moisture needs to be able to move through the walls to keep them dry over time....plastic will block that and one side will be cold causing the moisture to condensate (come out of the air) and the condensate will causing mold....