I guess that I was thinking as much about Canada as North Dakota when I set up the hypothetical question.
It appears that the western part of Saskatchewan and Alberta are very dry. I would assume then that the migration will get nudged to the east into Manitoba, eastern North Dakota, and maybe western Minnesota. Or, will the ducks just find big water in Saskatchewan and try to overfly the Dakotas entirely. That does not seem to be a likely scenario given that it is so dry way out west. But, I don't know. I am just guessing. Hunting could actually be pretty good this year, if you are in the right spot. One of our best shoots ever was in 1987 when it was pretty dry. In 1991, when it was really dry, we did very well on geese but not the ducks. They always leave you guessing.
Didn't the reports say that breeding mallards are down 31% since their peak three years ago. And, spring pothole counts were down 41%.