in similar fashion to what SteamMover does to your Steam games, you should be able to move the folder and setup a link to the new location, you would still need a shortcut (of sorts) in the original location.
You can use steam mover for this purpose just point its source to your mydocuments folder and destination to the new parent folder.
Or use the built in windows cmd "mklink" - Creates a symbolic link.
MKLINK [[/D] | [/H] | [/J]] Link Target
/D Creates a directory symbolic link. Default is a file
symbolic link.
/H Creates a hard link instead of a symbolic link.
/J Creates a Directory Junction.
Link Specifies the new symbolic link name.
Target Specifies the path (relative or absolute) that the new link
refers to.
Move the save folder to the new location eg d:\NEWsaveFolder
then at "command prompt" type
mklink /J c:\OLDsaveFolder d:\NEWsaveFolder
a special shortcut will be created in the original location to the new one and not take up any space.