It is pretty hard to imagine any particular set of conditions short of total planetary surface destruction that would make all extremophiles go extinct - and as long there is enough of them, they will start spreading again.
Any particular species, including humans that lives on Earth is unlikely to survive catastrophic changes - but life will come back and spread into the newly freed and opened niches, just as it did before multiple times.
Any particular species, including humans that lives on Earth is unlikely to survive catastrophic changes - but life will come back and spread into the newly freed and opened niches, just as it did before multiple times.