Limit Global Inventory vs Individual SKUs

Hello, we are looking for a way to limit inventory globally, instead of individually. We make garments when ordered (and do not have inventory on hand), so to us, it does not matter if someone orders a large or a small. So instead of limiting inventory based on each individual SKU, we would like to do so globally. As an example, we want to limit the total amount of orders for a garment collection to 65 (total, across all SKUs). Otherwise, we would have to guess which garment will be more popular, and at what size, and spread out the 65 orders that way. Is there any way to do this? I saw that someone recommended limitify with a workaround of using costs.. but that doesn’t seem to work for us.