What distro would you choose if Debian goes under?

[Jason]

I was under the impression that most of the Ubuntu packages are basically taken from Debian unstable. Is that not so?

You're right. It is based on unstable according to wikipedia. Edited my post to reflect that. Thanks for telling me so I'd look into it.

[Jason]

Ubuntu packages are based on packages from Debian's unstable branch, which are synchronised every six months. Both distributions use Debian's deb package format and package management tools (e.g. APT and Ubuntu Software). Debian and Ubuntu packages are not necessarily binary compatible with each other, however, so packages may need to be rebuilt from source to be used in Ubuntu.[37] Many Ubuntu developers are also maintainers of key packages within Debian. Ubuntu cooperates with Debian by pushing changes back to Debian,[38] although there has been criticism that this does not happen often enough. Ian Murdock, the founder of Debian, had expressed concern about Ubuntu packages potentially diverging too far from Debian to remain compatible.[39] Before release, packages are imported from Debian unstable continuously and merged with Ubuntu-specific modifications. One month before release, imports are frozen, and packagers then work to ensure that the frozen features interoperate well together.

Source: https://en.wikipedia.org/wiki/Ubuntu (under history)