the ultra running circuit
I wore Buffalo mitts on the four times I started the High Peak Marathon, which is 42 miles in winter across Bleaklow, round the Derwent watershed, and it usually snows. Temperatures are often below freezing: Buffalo mitts are without doubt the best.
They are flexible enough to change gear using Shimano levers: obvs gear end shifters are easier. When soaking wet I have rtaken them off, squeezed them out and put them back on: still not cold.
But no one will listen to me on this: word of mouth is not as powerful as the marketing behind expensive gloves full of cheap synthetic insulation that will get wet and make your hands very cold.
BTW marigolds were used for ice climbing: windproof, waterprrof and if big enough you can wear thin woollen gloves underneath. IMO better than the expensive cycling gloves.