If you lose your DLC progress, the same manual restoration method applies.
Inside the win64_save folder, you will see several .bin files: : Typically your Autosave file.
Advanced tips (power users)
Managing your save data on PC is important for backups, transferring progress, or troubleshooting "save data lost" errors. Save Data Locations
Tip: If you plan on manually editing save files or moving them around frequently, it is often safer to disable Steam Cloud temporarily to prevent the service from constantly overwriting your manual changes.