I am considering hiking the A/T through the Great Smokey Mountains Nat'l Park. I'm considering to do a south to north hike. To have shelter space available, I a mid to late April (2012) hike would be best. Is this early enough to miss the south to north thru-hikers? I've hiked only 66 miles of the A/T in Virginia and Vermont. I thought I could average 10 miles per day hiking in GSM Nat'l Park. Does this make sense? Any advice is welcome.