This is for repairs, not prevention, but I also get cracked hands and find the bars of Climb On! to help with quick healing. They're meant as a quick repair salve for rock climbers hands. You can get a 1/2 oz or 1 oz tin at places like REI and they are expensive ($5-10) but last a long time. Scrape off a small amount with your fingernail and pack it into the cracks on your hand, then put liner gloves on before going to bed.
Also, off trail in the winter, try to avoid washing your hands in very hot water, which is terribly drying. I recently went away to a place that didn't have hot water for a week and came back with my hands healed!