"Your entry permit is all you need to camp at Lone Pine Lake."
I hear I may want to descend all the way to the Portal after camping for 4 nights and summittimg Mt Whitney. If I do that it probably will be too late to hitch to LP for my car, go back to the portal for the rest of my group and drive back to Reno.
Can we stay at those walk-in campsites right at the Portal? What are my chances of catching a ride to LP early the next morning?
Frank, I saw your question on fb, too. The answer is yes, of course you can camp in those walk-in sites. They are just that: available to anyone walking in and claiming one. If they are full (probably never happens, especially this summer with the parking restrictions), there are more below the main backpacker parking lot -- the Ravine camping area.
Map here.
Oh yes, about those
WAG bags...

When you come off the trail in the evening, the
first thing you will want to do is unload those WAG bags into the receptacles right by the restroom at the trailhead.