Roncruiser, parking at the portal is your biggest issue. If you can reserve (or obtain when you get there) a camp site for the duration, that would be the very best, especially if it had several parking spots. The others in your group could then have a spot.

I am not very good at the campsite info issue. I know there are always plenty of walk-in sites at the trail head, but those are only good for one car the night before the hike (due to the one-car-per-permit restriction). I believe (but NOT sure) there are some first-come-first-serve (non-reservable) car-camping sites. Best info I have is what Versatile Fred wrote some years ago in the Orientation Notes.

If your group is all hiking on a single permit, then you will only have ONE permit to park at the trail head parking. So the additional cars will need to park elsewhere. That's why a camp site might work best.

They can also park down in Lone Pine, but then you have the transportation/shuttle issue to the Portal. Parking accommodations in Lone Pine are given at the bottom of the first post in the Parking and Road Construction thread.