Get the SXL. You'll have more than enough room to accommodate the larger size, it's easier to cook on, easier to feed, and if you do use it later in the year you'll be happy to have the larger box.
I'll second getting the SXL for the Redcliff. That's the stove I went for mine. It doesn't weigh much more than the next size smaller, and like slowelk said, is much handier.
SXL. Better to have more heat than less in those late season hunts. If things get too warm you can always ventilate by opening doors or raising the snow skirt.