I'm going to attempt to get a walk in permit entering cottonwood lakes and exiting whitney portal for a five day hike. Do I have to go to Lone Pine to pick up the permit, or can I pick it up anywhere in Inyo, such as Lee Vining? How critical is it to be there at 11am sharp? I'll be going in peak late July/ early Aug time. I'm trying to figure out what days would increase my odds of securing both the entry and exit I want. Pick up permit on Wed for a Thurs entry, Sunday summit, Monday exit... or pick up permit on on Thurs for a Friday entry, Monday summit, Tuesday exit...or any combination thereof. Or am I thinking too hard and it doesn't really matter?