Thanks, Will. The can of concentrate is in the neighborhood of 48 ounces so I will follow your advice and include it as part of the 6 gallons. I appreciate the advice. It confirms what I was thinking.
I love this particular fruit blend from Wally World! Last time I used this blend, it made a DB that tasted a lot like Riesling with a hint of pineapple and peach so I was glad to find the forgotten can of Riesling concentrate in my supply locker. At least I know the flavors will all "play well together".