I too would definitely recommend reserving shelter space at least 2 weeks in advance if not more for this time of year. Some shelters will be fine, but others like Spence Field, Icewater Springs, Silers Bald, and Double Springs Gap can fill up quickly sometimes, especially weekends. There is a specific backcountry reservations number that you should be able to find on the Smokies part of the NPS.gov website. Sorry, I don’t know anything about a shuttle. Let me know when you plan to finish. I might be in the area around that time and I’d help you out if I could.
zach attack