The Antarctic Ice Cap is slumping, not growing.
So what? So if it keeps slumping, my brother's house will have a beach. He's above the 10 meter line for Greenland so he's not worried that much.
Ditto my sister. She's going to sell in May, after the school year is out. They are moving above the 100 meter line.
If the shelf lifts off the terminal moraine we don't know what's going to happen, but it could happen over the course of a few years, or months, or weeks. How many holes have we drilled in the ice of Antarctica? How fluid is the ice at the bottom? At temperatures near freezing the flow rate is nonlinear. And a house is a thirty year investment. The resale value is what people are thinking about global warming in 2038, not 2008.

Just be sure to be far enough away from shore so that salt water doesn't get into the well.