How can I change where SourceTree stores its FETCH_HEAD and config files?

[dr_eck]

git was clogging up my OneDrive with all of the changes I make to files while programming, so I moved all of my repositories off of OneDrive.  Unfortunately, SourceTree is still saving several of its configuration files (config, sourcetreeconfig, sourcetreeconfig.json, FETCH_HEAD... etc) in a .git file in one of my Visual Studio 2015 project files.  (No, I'm not still using 2015!)  How do I tell SourceTree to store these files in a different folder of my choosing?