add_filter( 'woocommerce_upsells_total', 'wc_ninja_edit_upsells_total', 10 );
function wc_ninja_edit_upsells_total( $limit ) {
	return 8;
}

add_filter( 'woocommerce_upsells_columns', 'wc_ninja_edit_upsells_columns', 10 );
function wc_ninja_edit_upsells_columns( $columns ) {
	return 4;
}