Splurge and stay in the lodge. Take your time the next day in the visitor's center and do then 8.5 miles to Springer and stay the night in the shelter. Next day officially start your thru hike. The approach is really beautiful and is really not that difficult unless you are trying to do a 20 miler your first day on the trail (you shouldn't be!). I did 10 miles or less per day for the first week of the trail. Was probably underkill but I didn't want to push it as I wasn't in ideal shape. Yes, the stairs are hard but not that hard. Sheesh!