A data storage device comprises storage media including physical data blocks. The data storage device comprises a storage circuit. The storage circuit compresses a user data block into a compressed user data block before storing the compressed user data in one of the physical data blocks, leaving an unused block portion of the physical data block. The data storage device comprises a remapping circuit that remaps the unused block portion to an opportunistic block address. The data storage device comprises a circuit that stores data in the unused block portion.