The point about the Challenge, as I see it is more about getting to have a beer and / or a cofee with people that you have come to "know" on here than the actual photography.
Bill's original idea, the "one camera, one lens, one roll" concept, was just a front for getting down the pub, but with a purpose.
It's become (becom
ing) more like an annual Leica Forum User Group meeting for the whole of Europe, with a venue that changes each year. But it is, of course, a lot less formal than that. It's all a bit ad hoc, and much the better for it in my opinion.
There must have been at least half a dozen countries represented last year and I am pretty certain that we all had a great afternoon, despite the weather. Hopefully, in Paris in October, we can see some improvement on that aspect! (It's even been rumoured that we may have a trans-atlantic representation this year, which would be excellent)
So, if you want to organise a Vancouver challenge, why not? Set your own rules, you don't have to use Bill's if you don't want to.
But, I still think that "Rule Number 1" should be "enjoy yourself".