As a person who walks most places and who used to bike everywhere, I think a lot about what parts of the body need the most warmth, and where it needs less. I do not tolerate cold very well. But that doesn't mean it is ever too cold to go out on a winter day. I have lots of knits for that, and I don't think "too cold" is a good excuse considering the pile of knitwear I have.
I know that the head leaks a lot of heat, and keeping the neck warm is very important. For a sweater, the parts that need to be warmest are the neck, yoke, and front. So, doing slipped-stitches, garter, and stranded work up top is a good idea, and closing a cardigan at least from the neck to the chest is a good idea. The rest can be lace as far as I'm concerned.
I've had this hot pink sweater for years, ever since a friend "trash-picked" it for me.* This was a Jones of New York hand-knit sweater in single-ply bulky-weight yarn. As it's not in merino wool, I couldn't wear it comfortably as it had a high turtleneck, and it was itchy. (The only wool I can wear is merino.) Since before I was a sweater-knitter I'd wanted to remake this sweater. I finally started about a month ago, and used my new construction style, with lace below the yoke and on the lower part of the sleeves. It fits very snugly, and is great on frigid days.
This sweater will become a pattern. Once I get this current one down, this will be easier.
* We were living in a university neighborhood, where students regularly put out bags of perfectly good clothing. My friend couldn't pass up a good piece of clothing.