I have complained in summer of losing sensation,
@Milkfloat , as well but my fitter advised me against changing shoes and made other adjustments. I still lose sensation in the toes on long summer rides.
However.
I think there are multiple causes, consequently;
I've loosened the straps today
Longer winter socks up to the knee
Wiggled my toes (there is room)
Alternated pulling up with pushing down for some sections
Added two more layers up top
It's helped. But not cured the situation. I paid more attention and noticed my thighs are stone cold too, so maybe extra leggings of additional bib shorts if it drops below zero again.