[Monkeybrain]

The problem with any waterproof glove is they rely on a membrane of some sort to provide the waterproofness.

The constant flexing that you gove a glove just from gripping the bars means that this membrane breaks down over time, so they aren't waterproof forever. Then there is the issue of wind chill against the glove that transmits to the hand.

For that reason I've stayed away from mega-expensive gloves, I always found ski gloves good value and very warm.
If you have a real problem go heated, at the very least look for some of those Vulcan gloves, the ones with only 3 fingers so you have some fingers together, they keep each other warm them.

Best alternative, a fairing.