> how did the previous sentient species deal with it

I like your thinking :-) It's the kind of fantasizing that I'm convinced is at the core of human progress, based on hardly more than a number of currently unknowable "what if"s.

It is, as you point out difficult to know if such a species could have existed. But if they did and if they tried to survive, we might be fairly certain that they failed barring something even more fantastical, currently only to be found in the darkest corners of youtube.

The real utility of this line of thought is IMO how we might try to survive the same conditions, since there is no real assurance that it could never happen again. We don't have the answer yet, agree.