I think most places with a dress code would allow opaque tights and a suit jacket. But I'd also thought that the office dress code had been greatly relaxed in the past few decades, and hopefully the WFH revolution will put a dent in what remains.

Are there offices that still require skirts for women?

I know that used to be a rule many years ago, but I was under the impression that slacks or pantsuits were acceptable business attire for women just about everywhere.

This is true, but it can be very expensive depending on the dress code and what's in style/available in stores. I'm female and fairly curvy (38-27-40) and my options when I worked in person were often a cheaper dress/skirt that fit (due to there being professional dresses/skirts that didn't require tailoring) or taking every set of pants I bought to a tailor and adding a bunch to the price.

Also as a female that wears both sexes's clothing, the fabric on women's clothing is far thinner and less insulating than the fabric on men's clothing: I'm substantially warmer when I wear men's clothing (but again, that's not professional). On the other hand, women's clothing is softer and stretchier.

I work from home and in my pajamas now, but there are other variables contributing to the male/female office temperature debate.

Personally I think offices should just have 2 or 3 zones and let people work where they're most comfortable. It would probably be the most productive too.