Icestrom eggs are only found in blizzard-like conditions atop mountains greater than 3,000 meters tall. Blizzard conditions of cold winds and blowing snow actually provide it shelter from the sun above that would otherwise melt the egg before it hatches.
Icestrom creatures live atop the coldest mountains in Ark and are known for being so massive that, when they move from one position to another, they look like giant avalanches. In fact, due to their largeness, Icestroms are generally the cause of avalanches.
Thankfully, no major residential hubs lie at the base of mountains that Icestroms inhabit. The potential for danger would be much too high.
Sometimes the sun, in the summer months, can cause Icestroms to shrink in size but they usually recoup all of their mass in the winter time.