Yeah, what I have done in the shutdown script rc.reboot-cd is if growisofsseems to imply that growisofs will know if there is enough space left on a mini-DVD to save a session.
returns with $? -ne 0 then the script assumes cannot burn to that DVD and
will ask for a new one
...that's if I got the logic right, as not yet tested.
...also assuming that growisofs will return a non-zero value if cannot burn to a DVD. I do know if a DVD is closed, it returns value 255.
Anyway, 20th October iso now available.