I'm from the Netherlands but the climate isn't that helpful. Women here bike in rain, wind, frost, hail, storm, snow and ice, sometimes all at the same time.

The upright riding position solves most elegance problems: If you can walk in it, you can bike in it, and the posture is elegant itself. A warm winter coat can be very elegant, and if you ride upright the sleeves won't creep up your arms and the front and shoulders won't fold in a way that leaves space for the wind to blow through. They don't sweat of course, that's a matter of slowing down before heating up too much, hats, gloves, scarfs and earcovers can be useful in the cold, but can also be adjusted and used to manage body temperature to prevent sweating.

With fenders, a fully covered chaincase and mudflaps there's no reason to wear different clothes, and only heavy rain could spoil the fun of looking good while riding. Most of them will use an umbrella, but for longer trips rain gear goes over the regular clothes, so they will still look good on the destination.

In spring and summer coat guards/dress guards can be useful for elegant long dresses. There are special 'skirt saddles' but they are not necessary and out of fashion since the 50's. With a step through a mini skirt doesn't reveal too much if she pays some minor attention. Some dresses will look particularly sexy while riding, because the riding makes the buttocks stand out through the dress, but I think that's hardly ever unintentional. It's also not completely unusual to see girls riding in an evening gown, accompanied by young men in white tie.

In general, most women who are elegant walking are elegant riding. They sit very straight up, back slightly hollow, shoulders straight, elbows in and chin up. Others will quit elegance while riding, and make it look like biking is hard work. With a strong head wind, no one will keep a particularly elegant posture.

This video shows normal winter cycling clothes, and spanish girls who adapted quite well.

This video is probably a good impression of how average women in the Netherlands dress 'for' cycling through the year. Cycling isn't turning them into elegant fashionista's, if it's not there cycling won't help.