Hi.
Please read this regarding WebDAV and free space on system partition: No enought disk space
If you want to change the location of your vault, copy the complete folder where you find the masterkey files with all its sunflowers to the new location.
Then open cryptomator, select the vault and press „-„. This will delete the vault from the list. Then press „+“ to ad the vault again, but select your new location of the vault.
To ensure that your vault is synced to gdrive, open the gdrive backup and sync app, and select your new vault location as sync source.