Managed to keep toes warm with usual thermal calf length socks under tights and overshoes but the two things that help me are a layer of foil under the insole and a sandwich bag over sock inside shoe. Both are minimal next to nothing thickness and add just enough help to be worth effort. And like me, cheap.
I've never tried the foil but I carried and used sandwich bags during TransAm. Midfoot cleat setup doesn't work well with normal toe/shoe covers. I've also got a pair of Assos windproof socks which are pretty good and Dexshell waterproof socks which are toasty.
Managed to keep toes warm with usual thermal calf length socks under tights and overshoes but the two things that help me are a layer of foil under the insole and a sandwich bag over sock inside shoe. Both are minimal next to nothing thickness and add just enough help to be worth effort. And like me, cheap.