Re: How long would you go for?
For the record, the US program limits stays to 15 months (two summers and a winter) at a time. However, there are people who cumulatively have over a decade's experience on the ice.
Also, to answer one poster's question: yes, there have been a number of couples who have gone to Antarctica together.
As for 40belowJoe's comment about being a loner: that is a good quality to have, so long as it is accompanied by an ability to get along with others in close quarters. Spending time in Antarctica requires being able to deal with isolation and crowds.
Antarctica is far less isolated than it used to be. The three US stations have internet and telephone (though only 9 to 11 hours per day at the South Pole). The field camps may have less access to communications, but are still connected.