Are you playing on a server? Think about it like this: Why would you be attacked by goblins, trolls (and iirc the fenrings shouldn't run around in the mountains outside anymore as well) ... in the mountans? That is actually not possible in the vanilla game. Or at least shouldn't. Might someone be trolling you?
Idk about the 2nd type of blizzard but whenever you're in the mountains - set up several portals. One down the hill, one up and possibly several others so you only need to navigate for a few 100m at max from portal to portal as the landscape is quite deadly, esp. with the hunt raid. Put your portals on top of the giant, steep boulders with ladders to get up (on top) and you should be fine. That's really all I can say ...
(i'm assuming here that you were actually on top of a mountain with no other biome nearby)