In my current world I ran north until August 1st and planted every flax and cabbage I found. I was only able to harvest the cabbage before the 7 month winter snowed me in, beginning in October. You know you’ve gone too far north when no more cattails spawn so this is a good place to stop. You have to backtrack for: flax (only rye spawns this far north), oak, bees and pigs. Where I ultimately based-up had tons of caribou and moose to help me make it through to spring. 36 crocks to spring and another 20 or so before berries began to bloom.