I believe we are only limited by our means of travel. Since there are no roads to drive on, you would need to either secure some form of ground or air transport. Many people go hiking and backpacking every year, and then post their travel photos. Pretty sure you can get dropped off and freely walk south until you freeze to death. South pole much much colder than north pole due to land being below freezing vs ocean which can’t get below 0c underneath the ice. South pole has never even reached 0c (at least since measurements have been recorded).