aya, them frozen places are tricky. Fun fact, if you smooth the ice or build walls/floors with it, it wont melt. My favorite trick is ice crafts. keep them stored outside and trade them to the caravans in huge numbers.
I had managed to establish it as a successful fort within a few hours, trolls were turned into mush as soon as they entered the fort, we feasted on plump helmets and mole dog spleen.
And then my computer fucking froze so goddamned hard that I had to hard reset killing the fort with it. I shut down and just watched h3h3 while taking a bath. I'll probably revisit it later, but right now I'm more in the mood to play adventure mode or another game entirely then open another fort.