On Tuesday, March 19, 2019 at 11:12:17 AM UTC-5, wrote:
On Tuesday, March 19, 2019 at 11:51:27 AM UTC-4, Tom BravoMike wrote:
Today (March 19, 2019), ArcticShield Men's Boot Insulator price reduced on Amazon to $14.35 (medium size). Just have ordered a pair.

Thanks for the tip. Alas, size "medium" is only claimed to fit mens' shoe sizes 8-9. Also one reviewer on Amazon said this:
"... they are sized too small. I wear an 11.5, so I ordered the XL (12-13) to be safe. I tried them on 3 different pairs of uninsulated boots, but none of them fit. Not only are they too short, but the bend for the ankle is all wrong, resulting in the toe not fitting. I will be returning and see if I have better luck with the XXL. Update: The XXL weren't much better. Slightly easier to get over my boots, but the fit is so tight ..."

OK, so I got them today (medium size). Thinner than I thought, but will have to try them out in cold and wet conditions. My size is 8.5 and they fit my shoes without any problem. I have ordered another pair for my brother immediately. Flying or hiking in the woods, they may provide SOME additional protection. No big risk at $13.40 (yes, the price went down even more).