I saw a movie which I seem to remember was set in the snow-bound arctic etc. All I remember is that at the end the lead female character instantly aged decades & died on the spot... but I can't remember why. It was set in a blizzard. This is vague but does anyone recognise it?

Have you tried looking at "league of extrodinary gentlemen" ?


The League of Extraordinary Gentlemen (2003) - IMDb

Lost Horizon (1973)
Starring Peter Finch, Michael York, Liv Ullmann, Olivia Hussey, Sally Kellerman, Bobby Van, George Kennedy, James Shigeta
IMDb synopsis:
This retelling of the classic tale of James Hilton's Utopian lost world plays out uneasily amid musical production numbers and Burt Bacharach music. While escaping war-torn China, a group of Europeans crash in the Himalayas, where they are rescued and taken to the mysterious Valley of the Blue Moon. Hidden from the rest of the world, Shangri-La is a haven of peace and tranquility for world-weary diplomat Richard Conway. His ambitious brother, George, sees it as a prison from which he must escape, even if it means risking his life and bringing destruction to the ancient culture of Shangri-La.

Lost Horizon (1973) - IMDb

Here's Part 1 on YouTube:
http://www.youtube.com/watch?v=OTFS4MSKgH8

This is a remake of the 1937 classic.
http://www.youtube.com/watch?v=SxKoaIq6DcY

In both, the younger brother falls in love with a girl from Shangri-La who claims they are keeping her prisoner. When he takes her beyond the influence of the valley, she ages rapidly and dies. She has lied to him about her true age.