How long would the Earth last if the sun became a black hole?

[Radar]

There would be less than a week to organise a heated space, and I'd bet humanity couldn't stop arguing long enough to do it. We would need a population of over a hundred to survive.

That is the minimum if we have a stable enough environment to live in which will not be the case. Requirements to keep up the technology that would keep humans alive are much stricter - hard to estimate how it could be pulled off in the long-term.