As of now there are 4 seats unselected in forward cabin and all seats in rear cabin except row 9 and 11D. The worst outcome if two or three upgrades clear (if only one, then they have 2 seats together in coach and can easily play with that) would be something like 10L and 12A (+maybe 10A) - i.e. scattered. Chances are decent you could work out some swap with either 12D/G or maybe 11 or 15A if they're kind and get pretty close.