So, they went to Hoddmímis Holt, a mystical location foretold to shelter them through Fimbulvetr.
If you thought the winter in Game of Thrones was bad, you obviously haven't read the Poetic Edda. See, before the Ragnarok (the Norse apocalypse), came Fimbulvetr, AKA an awful, mighty winter.
Tasked with the tremendous responsibility of repopulating the world in the wake of Ragnarok, Líf and Lífþrasir needed a hiding place. So, they went to Hoddmímis Holt, a mystical location foretold to shelter them through Fimbulvetr. Here, in what scholars suggest might be another name for the world tree Yggdrasil, they hid and survived.
Apparently, morning dew was all the rage for sustenance back then. Their survival and the concept of a new world emerging from the old one is a theme common in various mythologies, symbolising hope and renewal.