OK, I think I freaked some guys out with the idea of designing and knitting a superbulky sweater in 6 weeks. So.... Howabout the by the beginning of May. There might just be a night cold enough in those northern climes to wear a sweater jacket.
Incidentally I found in my stash a huge bag of yarn called Griffolk that is very lofty. I'm knitting it either trebled or quadrupled on 15's. 2 st/in. I did swatches to test various patterns, and by the time I had was done (2 hours or so) I realized I had a panel the size of one front on a cardigan. It does REALLY go fast.
C'mon guys! Pull up your big-guy britches and whip out your big sticks. Let's make some manly sweaters!