Ahh sorry for the duplicate post then, thanks for the link.
In the meantime have worked around it by turning the number of items to display up and then hiding anything after the 6th item with:
#top-posts-3 .widget-grid-view-image:nth-child(n+7) {
display: none;
}
Probably not the prettiest way of doing it and won’t work on older browsers, but at least it won’t break with updates, etc.