Warning: this is potentially terrible advice as it disables your backup system temporarily, or until you remember to enable it again. It also deletes backups which might be needed if you need to restore a file that was modified during this period.
When downloading massive files like the 50GB tgz archives from Google Takeout on your Mac, you might consider temporarily pausing Time Machine backups. This can help avoid the creation of enormous snapshots that quickly consume your free space. It’s a bit perplexing, though—my Time Machine backup disk is always connected, so I’m unsure why snapshots are generated at all.
In theory, the operating system should delete or move those snapshots to your backup drive, but it seems to take its time. While most advice suggests leaving snapshots alone, some external tools can be finicky about free space. For example, Backblaze has complained when my internal drive space got too low.
To get an accurate picture of your available space, check the Storage Settings in System Settings. However, it can be disconcerting when the df -h command shows a much smaller figure. To quickly recover space, you can use Disk Utility’s “Show APFS Snapshots” feature to examine and delete any large backups.
Just remember to re-enable Time Machine as soon as you’ve moved those large files elsewhere. This approach does carry some risks: disabling your backup system leaves you vulnerable to data loss, and deleting backups may prevent you from restoring files modified during this period. Proceed with caution!