For informational purposes, another text editor I use, EmEditor, informs you admin permission is needed and offers the option to elevate - for both existing and new files (note: the whole text editor doesn't elevate, it uses a separate process to perform the save)...

On windows, if the file already exists, it just displays a dialog saying it is unable to save the text file...


and if the file doesn't already exist, it displays a dialog saying that you don't have permission to save in this location, with the option to save in My Documents folder instead...