I pulled my last savoy cabbage just before the first polar vortex, and I love that they keep through such cold weather. You're a zone colder than i am, but I think you would have to pull yours pretty soon. On the other hand, it should keep fine in your fridge until April.

How much snow cover do you have? Here cabbages would still be well under snow, and in that situation they would keep almost indefinitely. Outside it might be -31F, but at the ground level it is 27F. You can always help that along by actively covering the cabbage with a snow shovel.

Ha -- glib when I told my husband you still had 2 feet of snow, he wanted to come up to New England to keep skiing! We still have snow higher up, but in the yard, it thawed last weekend. More snow coming this week, though. Sounds like if it stays cold, it'll keep.

laceyvail -- I pulled some cabbage just before the first polar vortex, and left some in, just to see what would happen. The ones I pulled were good at first, but got dryer and shriveleier. The ones in the ground are fresh as can be--perfect for cole slaw, while the ones pulled earlier ended up only good for soup. I knew I was taking a risk, but was very happy with the results.