To begin with, I respect Chris' opinion as a resident. However, I was in your shoes 13 years ago. You are doing the right thing, pick one area and start working/scouting/knocking on doors (if you can find the landowner). Pressure is a relative term. If you are from Wisconsin, Illinois or back east, what a ND resident calls pressure is true for them, but is very, very light for us. The exception to this that I found is a large area around Devils Lake - hunted it twice, no desire to return as I do not want to pay $$$$. I would save the money and realize that the ND DNR is telling you that you are in the "prime" zone. I hunt zone 3 and am tempted to hunt all zones, then realize that we rarely find competition, except in some fields next to refugees on the MO river. My opinion is based upon my experience as a non resident, scratch hunter. No one is right here, just trying to help you.
Your time period could be awesome for field hunting and often is perfect. However, 2 years ago it was crazy cold around Oct. 6th-10th more or less. Many small potholes could be open or frozen by Nov, driving birds to larger bodies of water or to fields.
If you are field hunter great, small, frozen holes don't matter. Buy a North Dakota Atlas and Gazetteer. What state are you from? I have never bought a plat in ND, but that is a great tool. Try and pick up a phone book up there to find farmers numbers. Good luck.