"You can write an editor script to do this."
I'm not clear, are you referring to changing the positions of objects? If so, can you please provide a bit more information on how I might get started on this? Apologies if it's out of your jurisdiction, I might take this to Unity's Answers section.
Unfortunately, changing the sprite collection size probably wouldn't be the best option-- I'd need to change the scale so that the colliders attached to my objects would be affected as well.
I imagine other aspects of the game would be affected as well, like physics-based movements-- I'd have objects appearing to move 100 times faster than intended. Also, my tilemap sizes would need to be changed. This is probably just the tip of the iceberg. Unless I am missing something here (quite possible?), it seems like there would be very far-reaching effects in attempting to reduce the size of everything. Do you believe that there is an all-encompassing method of changing the scale of everything that wouldn't leave a trail of bugs and inconsistencies in its wake?