We're actually planning to bring a portaledge. Maybe not really necessary for this route, but the idea is that this will be a bit of a warmup/training climb for a trip to Yosemite in about six months, and some of the routes we have in mind over there will involve a portaledge. I've talked to others that have climbed Ozy and found a portaledge worked well to create a flat sleeping surface on Big Grassy.
If we manage to move fast enough on the first day on the wall we might even have time to haul to the Gledhill Bivi and spend the night there instead, but plan A is to bivi on Big Grassy and haul the next two pitches in the morning after we've lightened the bag by eating and drinking some of the contents.