I know few if any folks that lead regular lives that have the time to make the lemonades by the individual drink. Most including myself make it by the batch 1st thing in the morning. I don't have a problem with the cayenne and go ahead and add it when I make the batch. This will allow the Cayenne to "bloom" and it can get a bit too hot for some palates. A number of folks add the cayenne just before drinking each drink. The bulk recipe is posted in the FAQs.
I put mine in some Nalgene Sports bottles and carry them in a soft cooler with some of those refreezeable blue ice blocks to keep it fresh