But, they only stopped working when it was too dark to do anything, and then they basically sat or slept in a tiny, drafty, stuffy, one-room hut along with their livestock until the sun came up.

This is not entirely true though; people have lived up in the north for ages, and they certainly did not just sleep up to 24h per day for several months. "Just sitting" isn't how I'd describe it either, since those were the times for handcrafts, storytelling... etc. Expensive candles were were not the only source of light, for example around here people used specific wood chips they burned to get some light - obviously it's nothing like modern day lighting, but it wasn't just total darkness either.