Btw, instead of Antarctica, you could put your data centre in Iceland (with more or less the same pros, but fewer cons). And: people are actually doing that!
If you run your computers at about 60C, that's still plenty of difference.
You can also look into dumping your heat into water. Either ocean or freshwater.
Sure, boil the oceans we don't need em
It approximately doesn't matter in the longer run and on a global scale whether you release your heat into the ground, atmosphere or sea. It's all conducted around sooner or later anyway.