

Probably not without LVM or an external drive to restore from. Depending on which partition comes first, you’ll either have to extend the OS partition “leftward” or lop off the front of the data partition, and there isn’t a good way to do either nondestructively.
If you have LVM set up, you could reduce the storage partition, make a partition in the new free space, and lump it into the volume group for the OS partition.



No, the more the merrier, even if it’s pure publicity.