Best lotion/moisturizer for EXTREMELY dry skin?

I have super duper extremely dry skin on my arms and legs due to winter and my KP (keratosis pilaris) which result in flaking, red skin with bumps from the KP that bleed when even lightly scratched. My skin isn't really all that sore, but it just is so dry that I don't know what to do. So far, I've tried using Bath and Body Works body lotion with shea butter, Trader Joe's extra dry formula lotion, and a few just extra strength store brand products. What will help cure my extremely dry skin?