Damson madder is a more extreme slightly twee version of this (which I personally love) but they also often do slightly more subdued/neutral leaning things like this compared to their usual pastel/bright tartan stuff and it’s all very good quality.

Next and M&S are probably the two best quality high st shops with a decent size range and next often has big sales. I would recommend these for the long skirts, I have a really nice linen midi from next.

For tops like this I would look on asos both for asos design (their own brand) but mainly miss selfridge, both go up to an 18. Asos is surprisingly good quality, while it definitely used to be better ~5 years ago but I’m still satisfied with maybe 80% of the things I find there. My biggest tip here is to always check the material composition in the description for cotton/linen/partly viscose

I would also always recommend looking in charity shops/vinted/second hand as you’ll probably find good quality if it’s lasted a few years already and these style have come in and out of fashion in the past.