"...the Northern region...." and "..cold winters...." are not very specific. To people in Florida, Virginia has cold winters. Additional information about climate and your gas and electric rates would be useful in advising you.

First find out what started the fire and make sure you don't repeat that mistake. Like the idea of swapping a fireplace for a patio door. It is entirely possible -- even likely -- that building codes have changed in some ways since the original building was constructed. Hiring local pros, beginning with an architect, that knows what is and is not permitted is the best way to avoid expensive mistakes.

Jennifer, I think you know the issue here is more psychologically-related than interior design-related. My advice to you is to keep your goals inline with your values. As Donald said above: "If you want to be the kind of family that eats dinner at the table together every night then start doing it now." You're drawn to a minimalist decor? Make it happen. You start with the list of essential functions in your space (sleeping, working, eating, relaxing) then you equip each area accordingly. Nothing more. Which means you get rid of what doesn't serve one of these purposes. You mention you're a hoarder: find a way to stop that behaviour or else it could consume you and negatively impact your relationships. Things don't provide lasting soul-nourishing happiness. Relationship and experiences do. Chances are high your kid won't be interested in your childhood toys. Keep your top 5 favourite ones if you must, but no more than can fit on a small shelf. Boxes and boxes of makeup? Whatever for? You only have one face and makeup breeds bacteria so quickly. Delete Letgo and similar apps if they tempt you to buy random stuff you don't need. Instead of scrolling apps for random stuff to buy, do something else, for example, listening to short motivation inspiration videos like Mel Robbins, cleaning or exercising, etc. Any distraction to help you stay on course. Once you control the clutter, your space will make a lot more sense to you and decorating it will be easier. You can do this, Jennifer! :)

The mudroom is unfortunately small and the only drop zone is the the sink, so not somewhere you would actually want kids setting down anything. (Not that it stops them) Yes, it's difficult because I'm realistic that the clutter will be set down somewhere. We always have school papers and laptops and whatnot, so at least keeping it contained could be useful. But my husband disliked that version, anyway. He did have me talk through the idea someone here had to move the doorway, but with the plumbing and tight layout, it just isn't really doable (not without losing the sink, but he uses that a lot for garage activity cleanup and I don't want any of that in a sink where food items would be).