Have a pair of MT92s (and MT91s as well).
I think I saw a post from a month or so back about putting foil on the sole or insole to insulate them - but can't find the post anywhere - was it just simple all tape for pipe lagging, carpet / flooring ? or should I try for insulated / padded tape (if such stuff exists?)
Then I can have slightly warmer feet hopefully!
I just use some cut out space blanket in mine, you can feel the difference, but it's not a magic bullet.
I used normal tinfoil last winter and it worked a treat, but it was a right bugger to get out in the spring because it had fallen to pieces.
I got some wool insoles backed with foil for 3.99 from Amazon. Replaced the existing insoles they're much warmer when dry, and not much warmer when wet.
I'm fine with that, but YMMV if you're sold on pseudo orthotic science babble cycling shoe insoles.
I use foil tape, the stuff used for sealing round insulation sheets, pipe ducts, etc. Works well, I just tape it to the underside of the insole.
FWIW there's a notable difference between using SPDs, metal flats and plastic flats. I'm a convert to the latter when temperatures plummet.
I hear what you're saying Colin.
I only have SPDs as pedals at the moment.