I also work in an office environment, I recently just picked a pair of Wall's brand, heavy insulated overall type with suspenders for about $65. I have used them several times already in temps below 40 degrees in the morning and they keep me warm. I slip them on over my work clothes and swap out foot wear on arrival. they have zipper pant legs and zip down front bib, so they are easy to get of in the parking lot. my commute is about 25 minutes at 55mph, no issues.