how so ? they would fill 2 grids. I don't see them getting even close to 2 at the moment, so overfilling it wouldn't be likely.
if they get too many for 1 grid... then that's enough for 2
there's of course the possibility of an uneven split... say 40 x 620 and only 15 x 583 (for example) and the 620 would get their own grid and the 583's would be in with something like the CB500's who don't usually fill their grid.