One more update. I now have the room all closed in, and I can't believe how comfortable it is. It is hovering around zero degrees F in MN this week, and the new room is on average about 8 degrees warmer than other rooms in the house. The room is roughly 300 sq. ft. and has one heat register. I even tried a test and closed the register overnight, and still the room was 4 degrees warmer in the morning than the rest of the house. This room was super cold previously, and you needed a jacket on down there in the winter, even with the register wide open. The whole family will live down there in the winter...

Thanks again to everyone who provided guidance on this project. Great team effort!