tmux change default working directory of a session without attaching

I'm looking for a way to do something like this *without* attaching to the session. tmux attach-session -c -t ^^^^^^^^^^^^^^ Per tmux(1), there isn't a way to change the default working directory (new windows and new panes) of an entire session without attaching to it. I cannot attach to the session because I'm doing this in some automated scripts where attaching would break the automation.