I am one that hates wearing gloves, but the ones that have worked the best for me are the maverick gloves. They work pretty good as broken down by Glenn.
they are adequately warm for their thickness. IDK if theres a better option other then switching to NRS Toaster mitts.(that being Said I have never heard of the glacier gloves,nor tried them.)
i used to have the Toaster gloves and i found they were far too thick in the palm and affected my grip, which causes hand fatigue. that is of course, no bueno and basically a complete autofail. unless... one had a small diameter shaft paddle just for those purposes. which most likely isnt going to happen.
I dont paddle in as cold of conditions as much those of you up north, but when i did one january run last winter,under rare iced over conditions on the Rio- i didn't know what to expect,(i was a little skeered lol) so i wore the maverick gloves AND snapdragon pogies, and my hands were totally good like that. there was slush ice in the water, and ice sieves y todo (translation= and everything,no. )
infrequent river conditions for NM although it gets plenty cold here.
The other paddler i was that day with said he switched to toaster mitts and greatly prefers that setup after years of trial and error. easier to get on, and warm fingers cause they are together just like snow mittens, not separate. and no need for pogies that way. I would look at those for the coldest conditions, and the Maverick for the inbetween season cold days.