Weather can alter your trek thru SMNP. I spent 4 nights going thru SMNP (starting @ Fontana Dam Shelter): Russell Field Shelter (13.8M), Silers Bald Shelter (14.7M), Gatlinburg (12.5M), and Tricorner Knob Shelter (15.6M). The first night out of SMNP was @ Standing Bear Hostel (18.4M).
All mileages based on 2013 Awol Guide.