Wow, thanks everyone! What a response, I guess I better go whole wall! To clarify, I intend to do four walls - I guess I really meant whole bathroom rather than whole wall. Other than the sink, mirror and toilet there will be a long floating cabinet running from six inches above the floor to six inches from the ceiling. Plus on the primary 'uninterrupted' wall (i.e. no sink, toilet or cabinet) there is a transom, so even that wall will be broken up somewhat. Final point, this powder room will be used by children quite a bit, I have a five year old and a 2.5 yr old (no home daycare though!). I think I can live with the wear and tear factor - I may have to repaper in a few years, we'll see. If it is useful information, the ceilings are 9', so it will still be a lot of wallpaper! Despite all this, people still think I should go for it? Both my husband and I do love the wallpaper (always a good sign). Karin1, good advice about figuring out how many rolls I will need. That may dictate how I proceed a little. Thanks again everyone!

Cran, I am usually the one who needs a fire lit under me! Arapaho I also gravitate towards greens and yellows and those are the predominant colors downstairs. I made a concerted effort upstairs to use blue and white and taupe in the main living area and secondary bedrooms. Tina, part of the reason I wanted to leave off the chair skirt is because I wasn’t sure I have enough fabric for it. A large plaid or pattern repeat means just a club chair skirt can take 3 yards of fabric! So after I saw the bed I called the upholsterer and told him to leave off the skirt and change the legs to turned ones. It was a question of necessity as much as happy coincidence.

Thanks everyone! @Jinx That is the right one! Ive seen it in person and the colours are more like the picture I posted. @tartanmeup I never considered how it would look with the flooring. Maybe you are right that the contrast is too stark. I know the paper is dark and so I also have samples of the two. below. Do you like these better? Which one? One wall? All walls? What paint colour with it? Like the blue one above, the scale on this is bigger. I have samples of both and the colours (on my screen at least) are pretty true to the real thing. This is why I LOVE this site. You are all so so helpful! :)

Complicated wall paper patterns have the potential to visually shrink a small space even smaller. Could you add a high horizontal "chair rail" on the wall above the countertop / sink level and wallpaper only that back wall behind and above the sink and toilet with the mirror covering part of the wall over the sink and open shelves over the toilet. See how you like that before doing the other two walls. If you do only above the "chair rail", you get the pattern you like added without having the design over power your small room. You could pick a color from within the wallpaper for the rest of the wall. You might even consider a vertical "wainscoting" or paneling for below the "chair rail". You might even consider a faux window on one wall. Lighter colors -- white door and trim -- and pastel walls are going to give off a more open vibe than darker colors. https://www.houzz.com/photos/wallpaper-powder-room-ideas-phbr1-bp~t_713~a_3406-20866