(on rereading your post i found the other floorplan!) ... 3m x 3m is sufficient for the bath and ensuite ( there are a choice of drop in baths under 1400mm, an average toilet will fit comfortably in 800mm width (but aim for toilets that measure under 700mm deep) off the shelf 1200mm wide vanities are available with lots of storage and matching mirror doored medicine cabinets and a tiled recess would make the best use of the shower space (with or without glass doors but you'll need a screen to protect the edge of the vanity from spray) using the old linen cabinet will allow for the bigger vanity and a cavity sliding door for the ensuite would be worth the extra effort and create a better finish for your reno

Can you draw up a sketch, showing the length of the shower recess/layout of bathroom, as well as the width details. It's a bit hard to tell the size of the area with the photo posted. But, my initial thoughts are to agree with having a solid screen the same width as basin, then pivot door from that point. But 535mm is tight for opening.

Here is my finished ensuite. 1.8 x 1.8 m bathroom. it works well as a layout. the shower is 900x 900mm. the vanity is about 280mm deep and the sink hangs over the edge a bit (if that makes sense!). the shower door is 550mm wide. i havent yet had the towel rail installed but when i do it will be on the left hand side wall. thank you everyone for all your advice and suggestions.

Oklouise and Siriuskey and others thanks so much for input. I’ve attached the version we think works best, but would like to configure the other space as a semi ensuite with hall access also, maybe we need to include the corner storage space as I have shown to make it work. Siriuskey, I have taken your advice and removed internal angle walls for fireplace,tv and butlers pantry and have realigned the other small wall as mentioned. We will reconsider when we are at built stage, how to define the spaces...I am liking the idea of cured walls to soften the other angles. Just wondering if I could stretch the friendship and have one of you re draw the small bath room into that space as shown I would be very grateful.