Yes, the game is often needlessly cruel... but it's actually not that hard to run and grab your gear and run away. Just make sure you're buff naked to move fast, fill yourself up with lots of food (and frost resistance mead!), and have nothing in your inventory so you instantly grab everything. And don't forget to rest first (you don't want to try it without the Rested buff)

Then run run run...

It's actually not that hard in mountains compared to the plains... has anyone managed successfully to corpse run in the mistlands?

We all have had those frustrating moments my friend. Those things also can make for a fun adventure in themselves. Planning your gear retrieval can be exciting. If you get a chance in the future make a backup set of armor and at least a shield and weapon of your choice for the recovery in the event you need to.

@MyUrp1 I corpse ran the mistlands, it was doable but barely. It required bonemass and a lot of food

That is because you try to travel the montains at night, go at the day time and this high lvl wolfs will not spawn. Unfortunally in mistlands its not consistant with this rule ( it should be since its all the same for all biomes).

First let me say I feel for you. Deaths that seem arbitrary really hurt.

2* wolves only appear in the vanilla game at night.

So either you are modding to tame 2* wolves easier, in which case this isn't the game's fault, or you went into the mountain at night, or so early in the morning that the night creatures had no chance to despawn.

Therefore this is 100% avoidable, by staying out of a new biome at night, and only fighting there in the day until you have the food and gear from that biome.

Mistlands will give you nightmares, there you CAN have 1*/2* seekers jump you out of the mist and wreck you. Properly geared they will not 1-shot you, but depending on your reaction time, you may never get to act, as they can 2-shot you, even with top tier plains gear and food. They can also knock you into pits, water, or off high ledges, all of which are pretty much guaranteed death when you are in plains gear.