I know what you mean with " dressing for the schoolrun", you mean something you can throw on, and still look nice ( or even like you made a bit of an effort). Much nicer than jeans and a fleece, IMO.
I am a dress person too! People " accuse" me of dressing up or looking too elegant ( ha!) but I find that throwing on a a dress and shoes is so wonderfully QUICK a way to dress.
Also, Like you I am cury ( not as a euphemism for fat, but curvy in the sense of significant waist- hip ratio) and dresses look nicer, and are way more comfy than jeans, imo.
To me, a simple dress means the perfect balance between comfort and style.
The dresses in the OP look like they might look a but frumpy, but you don't know until you try them on. Also, a classic dress this style can look cool with a fitted ( leather) jacket and ankle boots.
My best dresses are from Whitecompany ( plain but can be jazzed up with scarf and accessories), and also Joules. Joules can look frumpy on the hanger, but good on a curvy figure.
Peopletree winner too.