Its true that Antarctica used to be ice-free.
It’s only since Antarctica moved to the pole that we’re even in an Ice Age.
There's an interesting book titled "When The Sky Fell" that makes sense, to me anyway. :-)
The "Sky Fell" refers to an ancient belief that the mountains held up the sky, and when the mountains collapsed (due to a shift in the tilt of the planet and the following upheavaling) the world was encased in clouds of vapor/smoke. ("Valley of the Shadow of Death" ???)
The "tilting of the earth's axis" explains The Flood in that as the earth tilted, oceans left their bed and sought out lower areas.
One guy posited that the accumulating weight of the ice cap tilted the earth, but that was later proven to be untrue as the bulge in the Equator counteracted that.
Lots of theories, but, IMO, the book above makes the most sense.
[sidebar] When I worked in the Middle East, I picked up a clock that showed a map of the world that was different from what I was used to (North America centric). Their map showed the Middle East in the center. Cool.
The book above shows the map of the world with Antarctica in the center, and Plato's description seems to fit it better that the common Gibraltar explanation.
Fun to speculate, in any event.