Решением оказалось использование свойств фильтрации
$rsSections = CIBlockSection::GetList($arOrderChild, array("ACTIVE" => "Y","CNT_ACTIVE" =>"Y",">=ELEMENT_CNT"=>1),false, array("ID"));
$rsSections = CIBlockSection::GetList($arOrderChild, array("ACTIVE" => "Y","CNT_ACTIVE" =>"Y",">=ELEMENT_CNT"=>1),false, array("ID"));
