You have a lot going on texture-wise so I'd probably keep it simple in terms of rug texture or there'll be too much going on at once. Warm would do well in this room though, so that's good! You mention it's away from the light outdoor area, is this photo an accurate representation of the lighting you normally get in this room? So in summary, you might want to have a look at rugs that don't have much texture, and are a bit brighter in colour to help brighten up the room. Below are just a couple of examples of rugs that could work, and one more neutral example.

Hi, did you mean to attach a photo?

Hi Sue, I think it would look amazing if you used some tiles with a bit of texture. The wood look tiles that are popular at the moment would be an example. If you chose a colour that toned in with your floor you would get a really nice cohesive look but with a bit of interest. I've attached a photo of a recent design of mine as an example. Just a suggestion!

without the plan of upstairs i'm not sure that my suggested changes to front wall will be suitable but instead of reducing the rear deck, taking space off the front porch would allow extra space for the kitchen without changing the front set back and, unless there's some special reason for the extra toilet could you consider different access to the downstairs bathroom to have a more private toilet with included handbasin with or without the extra sink in the dining area?.. there's enough space for extra storage for utility and dining area with a table for two in the kitchen and extending the floor of the deck to the rear and side fences would allow more outside sitting area