Spread for a large group

Grim Surveyor

I'm going to an event that could include up to 30 people. The organizer asked me if I could include as part of the event some sort of reading that would cover the entire group at once. Something where everyone had one card and then there is a central part of the spread to cover the event in general. I realize this will take about half the deck. I have worked parties before but always one at a time in series, never a group.

I have also done a spread where everyone goes around in a circle and pulls one card for the querent, but with no more than 7 or so in the circle. The 7 cards you pulled for other people in series are combined to become your additional reading at the end.

I searched the forum but did not find anything applicable. Has anyone ever done anything like this, or is it even a good idea? I would be the only trained reader at the event and I would have a slot of maybe 30 minutes to work in.

Greg