I would suggest you take out the cabinet that is to the right of the stove and use it elsewhere in the house -- perhaps in the bathroom or dining room with a hutch above it. Then, I would suggest you have someone install a lazy susan cabinet in the corner between the sink counter and the stove, meaning you would move the stove down a bit and have a small cabinet/counter top to the right of the stove. I would suggest you have the cabinets refinished in white and then paint the walls a pastel you like. If you would prefer white walls, then add white-painted crown molding and paint the ceiling a light neutral blue, such as Sherwin Williams Niagara Falls Blue. Then, I would suggest you choose a favorite accent color and use this sparingly in accessories like towels, pot holders, small vases or floral arrangements, and a valence above the triple windows. For a genuine 1940s look, you might have white ceramic square tiles with a rectangular red border installed as a back splash behind and above the stove. If you are replacing counter tops, I would suggest a light color such as white with a beige or light grey vein or striation for some sort of pattern. You might be able to find the same color and design in floor tile OR opt for a wood floor as another poster suggested.

Medicine cabinets have come along way in recent years. The best option is to get a frameless style and integrate it into a wall of mirror. You can mount sconces thru the mirror on either side of the cabinet. If you have walls on either side of the sink, you can put the cabinets to the side, integrated into mirror again. If you have an open wall in your bath, yo can get an extra tall medicine cabinet to hold loads of stuff. There are loads more on houzz photos. Just search medicine cabinet. Sometimes you have to hunt for the cabinet because they are so well integrated. Robern makes some of the best frameless styles, but there are a ton of others on faucetdirect.com. Many even come with integrated lighting for a very modern look.

Kind of funny really how many people would feel exposed and would not want to use the bathroom. The more I think about it, it's a bit like a public restroom with stalls (as stall walls rarely go to the ceiling or floor and have the added issues of gaps between the wall panels and doors -- which thankfully we won't have!). Regarding the humidity control issue, I should have clarified this is only for a toilet and small hand basin (not a full bathroom with shower). The main room on the other side of the proposed toilet is our dog whelping room where we will have young litters of puppies (when we have them). Further down the hall, removed from this room, is our training room where there are likely to be other visitors but the proposed bathroom would be quite removed from that area. It would be wonderful to find more windows like the ones that are up near the ceiling! That would certainly solve the issue. I'll have to scour the demolition/restoration places.

Clear any shrubs / trees / weeds, away from around the house - not saying go out with a chainsaw and slash everything down to the ground but make sure there is nothing higher than the window frames directly around the house or even leaning on the house. Taller tree's may be able to be pruned to allow more light through e.g. lift the bottom of the growth up higher by removing lower branches or thin out branches from within the canopy. Bring in as much sun as you can during the day. If you are planting a new garden, always look at the height of the tree's when they mature and if possible mix some trees that lose their leaves in winter so you obtain maximum sun. Check your insulation e.g. last year I added a new layer of insulation onto of my existing ceiling insulation. If you have dampness under your house maybe look at channelling water away from the house with what ever means you can afford e.g. professional drains right around the house or just dig trenches. You may wish / need to add black plastic over any clay / ground under your house if you are not on a flat concrete block based house. Open curtains during the day. Dress to the conditions. If you can't afford to heat the entire house just heat the room(s) you are using but make sure the non heated rooms get ventilation from time to time (especially lovely sunny days). Pile the blankets on the bed and even use a blanket over your legs if you are sitting watching TV or working on your computer. Think SUN SUN SUN. If you are renting and the house you are in gets very little sun, now is the time to start looking for something that gets more sun. Winter is the best time to look.