Sentinel-2A was launched on 23-July-2015 but the routine operations started in July 2016 after the ramp-up phase . Now with the onset of the austral summer, the first Sentinel-2A images of Antarctica are getting available (except for Dome C, which is a calibration site).
As of today only 9 images over Pine Island glacier are available for example. However this is enough to find three cloud-free images in the glacier's terminus area. Here I selected the images of 21-Oct-2016 and 04-Nov-2016 to run my simple glacier displacement script in Google Earth Engine (the code is here). I just increased the values of the maximum offset and the patch width because this large floating ice tongue is moving faster than San Quintin glacier.
The algorithm works well since the surface features (crevasses, etc.) are well defined . Also the high reflectance of the glacier surface in the visible increases the signal to noise ratio, while there is no saturation thanks to the good radiometric performances of Sentinel-2A.
 Jeong et al. (2016) Accelerated ice shelf rifting and retreat at Pine Island Glacier, West Antarctica. Geophys. Res. Lett. doi:10.1002/2016GL071360