I vote with SteveR@CBid on this topic after I used my 32 ct OtterBox to take about 40 cigars with me on vacation ... knowing I was going to a relatively dry climate, I charged the humidifier in the lid. Within 3 days, the cigars were quite overhumidified, something I discovered by finding many of the cigars at the top to be spongy ... I opened the box, removed the humidifier, left the box open for several hours, then closed it, but opened the relief valve. After that, I tood cigars from the bottom of the box and worked up and closed the valve after a couple of days.
IMO, you COULD use the box to temporarily handle an overflow situation, but since putting a little sweaterboxador together is so easy and inexpensive, why bother? ... in fact, why not put a couple of sweaterboxadors together? ... after all, you're going to need more and more "overflow" capacity anyway.