I missed any information about insulation being used, seems like you need to insulate the walls in SE Mich.
Would use foam insulation board over the 2x? and then strip the boards up and down, paint the foam where every board joint is so any gaps don't show. Butt the boards tight this time of year and loosely in Jan-March. Will get a small gap in the winter and close back up in the summer. Gives it a look that goes with all the exposed wood you have. Try one wall and look it over for a month or two before going any farther.
Just my thoughts, definitely like what you have done so far.
Ron