Do you have windows backup activated, as this can cause the problem as every time you change something it updates the backup.
Go to Control Panel, Folder Options and turn on Hidden and system files to check this. If you decide to remove any of the older backup files ensure you have any crital files saved elsewhere. Don't forget to hide these files when finished.
As you say it went full overnight i assume you left it on to do something.
was you doing a disc defrag , if so check how many restore points were made.
I once left a pc doing defrag overnight and it got stuck in a loop so every time it tried to run a new restore point got generated. As you may know restore points use up memory every time one is generated so that could be where your hard drive space has gone .....
if you were not defraging we might be able to help more if you give infrmation on what you was doing.
For temporary measures to get a few GBs back, right click the 'window' icon bottom left, select Command Prompt (administrator), type or copy and paste - powercfg/h off . This will disable hibernation and will give you room to install Treesize and Ccleaner if you wish.
If you need to turn on hibernation again then the command - powercfg/h on
- does it.