I understand that you don't want to purchase any more boots so I'm only chiming in with my own preference. My preference is to close the gap with a high shaft bootie....same with cropped flares. It's warm and looks streamlined.
FWIW, I picked up a pair of cheap sock booties by Design Lab at The Bay a couple winters ago. On sale I think I paid something like $50. The funny thing is that I get mad compliments and women want to know where they're from every time I wear them. I'm almost embarrassed to say. They have a similar black pair now but the heel is higher than mine...and also still full price.

Seconding the sock booties (bonus they don't rub the ankles the way stiff leather does) or tall sleek boots as the warmest option. I also did the nude knee highs, thin tonal statement socks, and regular black trouser socks to fill the gap.
This years winter strategy- skirts, dresses, and full length pants!

Marilyn - I had the same experience with a $50 pair of Design Lab booties from the Bay last winter! They aren't leather, but you'd never know,and they are comfortable as heck. I'm hoping the Blonde sock booties I picked up last month will work here.

Lisa p I think your Blondos look perfect!

As Suz and others have mentioned, I much prefer a higher shaft boot (not tall, but closer to the bottom of my calf than to my ankle bone) because I don't love the chopped-up look of too much of a gap on my lower leg.

The outfit dictates whether my socks match my pants, my shoes, both, or neither. My socks are mostly black, burgundy, or olive, which gives me an option for pretty much any of my shoes. I have some sheer black and nude knee-highs but I consider them only for dressier occasions and mild weather. I would freeze wearing just hose on my feet in the winter, but more power to those who can do it!

I am looking forward to seeing how this silhouette is worn moving into the winter ... you've got great ideas here and they seem practical for a more elevated casual or dressy look, which is what you do so well Lisa!