Sebastian called earlier from Low Camp. He and John had considered attempting Mount Shinn, the prominent peak to the north of Mt Vinson, but the weather seems to be changing and they decided to head back to Base Camp. It sounds like they had a great time up the upper mountain, and sort of surprised the other climbers when they stepped up onto the summit from a different direction!
They will organize their kit after arriving in BC, and will prepare for the flight back to Union Glacier, when the weather permits.