Comment 71 for bug 868904

The only work around I found was to configure redshift with manual location, and to have a script launched buy my window manager (I use 'mate') which automatically configures the location in the ~/.config/redshift.conf file.

Like this:
https://gist.github.com/ygbourhis/53f1ef5c6cb4b70ba910

So with this, redshift starts even with no network and will use the last saved position (in fact works the way it should).