I lived in a smaller urban area and it pant suits were verboten for all sisters. Then I visited a congregation in a large, urban area only to see elders' wives waltz in with pants suits and was told they were acceptable because women in the business world wore them.
Only goes to show that the BOE controls these things whether it be beards on men or pantsuits on women.
The difficult thing was living in an area with frigid winters and being told you could not wear pants, even under a skirt. Sisters just wore silk long underwear and black tights over that. I can remember nosy sisters checking to see if it was tights or long underwear checking to see if they had feet.
*** g76 8/8 p. 26 Dressing in a Modest and Attractive Way ***
For many women the pantsuit is quite practical and comfortable when shopping or for informal wear. But in some areas people would view it as unacceptable when, for example, attending religious meetings. A Christian woman is, therefore, wise to take into consideration the attitudes existing in the community where she lives. Thereby she can, to borrow the Bible phrase, ‘recommend herself to every human conscience.’—2 Cor. 4:2.
*** w75 8/15 p. 500 par. 8 Do Not Let Yourself Be Ensnared by Fads and Entertainment ***
If slacks or pantsuits for women are frowned upon by many in the community, likely some different style of apparel for public dress would be advisable for a Christian sister. During cold weather she likely could arrange to be exposed to the weather for shorter periods of time, or pause more frequently to warm herself. But in frigid climates, where everyone in the community wears clothing appropriate to the weather, such as slacks, surely it is proper for Christian women to do the same. In some places, pioneers have been aided thus to maintain robust health for putting in long hours in service.