I was getting the same problem some years back. now i use a pair of very light ankle socks the ones you use with trainers in the summer ( not thick so do not squash your feet ) and then put my normal socks over the top. that way you get the air trap people take about between the two pairs of socks. sound silly but it really works, i have been out this week 3 times and the temp has only been 1 or 2 up here we still have snow on the sides of the roads (snake pass), so with the wind when riding bet its been -5 I had my summer sidi vortice boots on and was fine.It really does make a big difference. and nothing worse when riding having cold feet. In the 1980s when i was a dispatch rider we all used to wear ladies tights in the winter as back then there was no base layers they really did work well. you looked a bit of a **** if you crashed and had to go to hospital, and it did happen to some of the boys lol. but it was really really common for us dispatch riders to wear them, so ambulance staff were used to seeing them on us lot back then.