feeding colonies

I have a couple colonies that have finally caught up to having a good population. The trouble with them is that they have not put up enough honey to winter them. I don't want to wait until Sept to start feeding. Feeding stimulates brood rearing. Feeding early when the supers are off will make the hive shut down brood production earlier. This will leave the bees more honey to winter on. Late feeding with the added brood rearing may last into late Nov. The bees will consume much more future winter stores than if the bees were fed early.
As the nectar flows slow, bees will take syrup down very quickly. Late August usually a strong colony will empty a syrup pail in three days.