M.C.
Have you seen the crocs with a shearling lining? My daughter currently wears them without socks, and her feet are always toasty (I know, because I constantly check). Also, last year, she wore her Uggs all the time. They also have a super warm, soft lining, and no need to wear socks. You can try both of them at Nordstroms. If there is a special brand you are looking for, I'd give Nordstrom a call - they have a very large children's section.