[dunham]

Can you add at least one row worth of empty items? They'll spill into an extra row and get stretched, but you won't see them.

[andrewingram]

That's a novel approach. The catch is that the number of items per row is fluid, so you'd have to overestimate on how many extra items you'd need, then you have the problem of not knowing how much overflow to hide for the parent container. Unless i'm misunderstanding your idea?