Hmm... try running this and give it a bit to finish. That will show all the base folders in GB, including system and hidden folders.
So I opted to do a nuke and pave and start all over and....
[doublepost=1534254309][/doublepost]...Success!
1. Booted into Recovery, wiped the internal SSD
2. Reinstalled High Sierra from Recovery
3. Created a generic admin account, logged in and ran any more updates (the only one was for iTunes 12.8)
4. Attached my external USB 3.0 SSD containing my CCC backup of my iMac
5. Started Migration Assisstant
6. Excluded Applications from the items I wanted to migrate, but left everything else checked off
7. Literally half an hour later, MA was done. It even showed accurate timings in terms of time left, etc.
8. Logged into my user account and everything was as if I was on my old iMac
9. Deleted the generic admin account I had created in step #3 above
10. Went to Mac App Store and proceeded to reinstall the applications that I had installed on the iMac. Went to individual developer's websites for apps that were not from the MAS.
11. One cool thing was that in my Dock, any applications that were not installed but had been in the Dock had a question mark instead of the application icon. Hovering over the question mark told me what application it was. Once I reinstalled the application (either from MAS or from developer's website) and launched it the first time, it situated itself back in the proper location in my Dock, replacing the question mark that was there before.
Checking my storage information, my System usage was back down to the normal 30GB rather than the 90GB it was using after having done the CCC restore.