My thumbs are long out of proportion to my other fingers so I prefer stretchy gloves. Usually the little finger glove length is longer than the finger itself, but I'm only concerned about whether the thumb binds or moves freely.

Flexible, stretchy gloves usually have compromised wind resistance so I get 'em a little oversized and use glove liners on really cold days.

So far I haven't needed the heavy winter gloves left over from my motorcycle days. Those have a knit wool/poly shell, GoreTex inner liner and good insulated padding. They're flexible enough to operate brake levers and shifters.

Last winter I got by with thin Bontrager Thermal RXL gloves, and occasionally added some thin poly glove liners for cold or wet rides. Good enough down into the 30s on dry days, or upper 40s on wet days.