Will the capacity of the Foggie Network depend on the number of 1TB Foggie Maxes sharing storage?

Yes and No.

First, Foggie Maxes will be sold in 1TB – 4 TB configurations.

Second, individuals can own more than one Foggie Max.
Third, the amount of storage available on the network does depend on how much idle storage is being shared on the network.  If everyone fills their Foggie Max up to 100% capacity, then there will be be very little free storage on the network.  Except…

Fourth — and probably most importantly — in addition to selling Foggie Maxes, we do have much larger, commercial miners that are becoming (or already are) nodes on the Foggie Network.  Those nodes will have much larger capacity — talking petabytes, not terabytes.

Note however, that those nodes/miners will be equal class citizens as each individual Foggie Max owner. Every node will be equal sellers of storage in the same marketplace (the Datamall Chain), and no one node/set of nodes will be preferred over other nodes.
In addition, more nodes helps make the network much more resilient from attacks, faster, and more highly available. If we were going to make a network out of only 3-6 large, industrial sized miners, that wouldn’t really be decentralized storage. That would be more like a centralized storage cooperative.