THis is just a summer cottage, no insulation, heat, etc. it was built by a farmer for my parents 50 + years ago. The pine floors aren’t even tongue & groove, just very irregular boards, and I have no interest whatsoever in the time or expense of refinishing them. The vinyl plank is purchased; my only question is about the type of thrasition to orde.

In general it isn't a good idea to mix a real product with a faux version of it. I did use wood-look tile in my guest house and we have real wood on the staircase, BUT I had the hardwood floor guy stain and finish the wood stair treads to match the tile. He got a very very close match and most don't notice the transition from tile to wood to tile. Why don't you like hardwood in the kitchen? This is my third house with all hardwood (except for bathrooms) and we've never had any issues. I would steer away from huge contrast and faux next to real.

First rule when working with two 'fake' products (you have wood-look tile on the main level and I am assuming you want wood-look vinyl on the second) = don't let them touch/be visible to one another. So....that means putting the vinyl on the stairs is 'out' (design wise). Now what to do? You won't like it but the easiest, cheapest, fastest solution = more carpet. I agree that you should change the current carpet. I am all over that like white on rice! The reason I say this is the cost of updating a stair to a new type of finish = very expensive. As in so expensive it could DOUBLE the cost of your project. Nope. Not kidding. So. I would go shopping for your new vinyl. That's SUPER important. Get it down to a few choices and then take THOSE choices carpet shopping. I would take a piece of the tile with you as well. You will then pick out a few carpet samples that you can 'stand' and then figure out which one melds the two floors (tile and vinyl) together to create one cohesive look. If in doubt, match the stairs to the MAIN floor. That is the public space where guests will see it. Traditionally upstairs are the private quarters and only the family members will see them/use them. The main floor is where the 'presentations' happen. It is important, design wise, to ensure the main flooring (your tile) is in tune with the flooring on the stairs. A bonus would be if you can match the stairs to the UPSTAIRS flooring as well. But it isn't as important. There you go. Sorry to say but you should keep carpet on the stairs until you can come up with a new budget to COMPLETELY redo the stairs. Purchase enough vinyl to cover the stairs (if you ever decide to tackle that project). You will need to save up several pennies to refinish that stair case...and bring it up to current code (that little flare at the bottom is expensive...like OMG WTF!).

No wood-look tile! Whatever you do, please do NOT put down fake wood against real wood. It cheapens BOTH products and makes things look awkward. Can you continue the shower tile onto the floor? Is it rated for flooring? If so, then it is possible to use a decorative tile at the base of the tub (I would match the colour to the cabinet) and then start the flooring with the 'shower tile'. I can't see the shower tile, but I'm assuming it is close to the original floor tile. If you absolutely cannot find something that is a decent COLOUR/texture match, then I would sacrifice the cabinet (or paint it...) and put down a darker floor that is the match to the diamond accents in the tub surround. In fact it might be possible to 'invert' the colour scheme (dark main tile with lighter 'diamond' accent). If you do that, you do NOT want a dark cabinet on a dark floor. Sacrificing the cabinet (possibly the counter top as well...but that's another concern) is the cheapest way to get this done. Just keep it in mind - a different (lighter) cabinet colour will offer you more options for your flooring. It could save your sanity.