What if the Drake Passage never opened? (climate, snow, record)

[deneb78]

How do you think the climate of South America and Antarctica would be different today if the Drake Passage never opened?

I wonder if Antarctica could have permanent settlements under this scenario. Certainly the cold shots that temperate South America get today would be much stronger. Buenos Aires might become more like Myrtle Beach, SC with regard to record lows.

[P London]

Temperate South America would be cooler due to the effect of the huge polar air mass of Antarctica. Places like Rio Grande, Montevideo, Vladvia and the general 'souther cone' would be only slightly colder but with much colder coldsnaps making snow more common.

Also possibly the joining of the two airmases (very cold dry polar & Tropical moist airmases) may course huge storms though i'm not too sure.