The Antarctic is actually pressed down by the weight of the ice so much that it is partly below sea level- if the ice were suddenly removed by teleporting it away the Antarctic could be seen to be in fact two island continents separated by a strait.
So, much of the Antarctic ice can melt without affecting sea levels at all; only the ice domes on land themselves will affect sea-level directly. The ice domes have never melted, even when the Earth was much warmer than today; nor will they. Southern England had a mediterranean fauna in the Ipswichian interglacial, and the temperature was perhaps 3º C warmer than today. Yet the ice domes of Antarctica did not melt.
If all the ice were to suddenly melt the land surface of Antarctica would recover isostatically untill the strait between the two islands disappeared; this would add to the total sea level rise, but once again, this has never happened since before the quaternary period, nor will it (unless there is a catastrophic release of methane clathrates, which I wouldn't neccssarily rule out).
Isostatic recovery is a very slow process, so we would wait thousands of years for this last effect to become apparent after the last ice melted.
I short; I think sea level rise will be a slow phenomenon, and we will have time to put some remedial countermeasures in effect before we have any 80 metre rises.