These one size fits most slipper socks are made with two colors and require no seaming, only an easy “gathering of bumps” to make the toe. Leave the “bump gathering” out and have leg warmers, which could even be pulled down over the tops of boots. Versions of these were sold years ago but the pattern seemed to be lost. If you don’t want to make an I-cord you could make a crochet chain with 3 strands of yarn. The length of the I-cord in the photos is roughly 5’ but could easily be 6’ for larger calves. Longer lengths can be made, or short rows could be added in the calf area if necessary. I have included as many photos as possible for ease of completing, but if you have questions, message me.