No it just would have been floating in space

I think the tesseract would be destroyed but the stone would be floating in space somewhere, but that is just my theory

I don’t think it would have been destroyed, at least not the stone, but maybe very hard to find.

I mean, Thor was pretty confident that it was destroyed, as if it's definitely possible.

Thor's belief that the Tesseract could be destroyed in the aftermath of Asgard's destruction is plausible. I mean... no way Thanos fist is stronger than the explosion of an entire nation!!! Ofc, the stone itself would likely be intact.

I don't know, it seems like Thor was confident that the stone was destroyed. He talked about the Tesseract, but likely meant the whole thing.

The stone would've survived. However, I don't know if the cube itself would stay intact. So for me that is undetermined.

It would have probably just been floating in space because the only known way that the stones could be destroyed was when Thanos reduced them to atomes by his own faight to destroy the stones by snapping a second time.