The CAA has been a late starter this year compared to 2012, and I expect it to reach between 100 and 250 km3 by the minimum. I'd be very surprised if it manages 50 km3 like 2012 and 2011 did.
The CAB, chief of the arctic, has seen a strong decline, giving 2012 a run for its money. Eyeballing the chart and considering the accumulated high arctic AWP, I expect the minimum to be less than 2016's and 2011's 3960 km3, and more probably above 2012's 3400 km3. But there's also good probability for breaking that record, with melting weather and a GAC. This region, as usual, is the big question mark.
And don't forget the Greenland Sea, where high export years get punished. I expect volume at minimum to be between 200 and 300 km3, though 2017 and 2018 managed to get below 50 km3.