Shout-out for arugula!
My wife and I experimented with some cool-weather crops this fall, our first time doing so since recently relocating to northeastern Washington state (zone 6). We planted spinach, kale, and arugula from seed in late September, but then winter came early and we had 2 hard freezes (when the temperature drops below 27 degrees f), 10+ frosts, and 3 snowfalls totaling about seven inches, all before the middle of November. I all but gave up on the crops, but as the snow melted off we were pleasantly surprised that things were still alive, and the arugula was nearly ready to harvest. Granted, the growth was rather stunted, but after spending a week covered in snow I was amazed we had anything. The spinach and kale produced enough to garnish a salad, but the arugula stole the show.
Note the frost in this picture!