The climate in MI can be rough, i spent my college years there and know first hand. I would suggest a triple pane glass package as your best option. With that said, i would consult with sunrise windows whom i recommend since they are based in your state and do make a fine window unit. You will find that window to be a much better option than pella and without the maintenance. Builders tend to push ineffiecient wood windows because that is all they know. I would not take the advice of a builder when it comes to window options.

You know, you might benefit from cross posting in the building a house and decor forums. Lots of folks there who might be able to give you some great advise.

Some follow up, if anyone is interested. I talked to the Kolbe dealer again. He said their prices are close to Marvin's and not to choose Kolbe for price. A bigger difference might be the dealer mark-up than the product itself. That dealer is a 45 min away and unknown to my contractor. There are also mixed reviews on yelp. My contractor is getting bids for Marvin from two local stores that are reliable. The one I met with yesterday was great (and came recommended by my architect and interior designer). Fun fact: since Marvin makes all windows to order, there isn't really an up-charge for a "custom" size. (I'm trying to match the windows in the front of my 1940s bungalow and some the dimensions are non-standard ). The Marvin book calls out sizes in 6" increments, but they can make windows to any spec, to 1/8".

@Melndo The walls are Benjamin Moore Rockport Gray: https://www.benjaminmoore.com/en-us/color-overview/find-your-color/color/HC-105/rockport-gray?color=HC-105 Our window is north facing as well. There is a large Japanese maple near the window so we don't get a ton of light there. I have the floor lamps, two table lamps and a light on the ceiling that isn't in the picture to make sure the room gets enough light. We actually use this room as a music room. There is a piano on the wall that isn't in the picture. Hope this helps! Glad you like it. :)