I also suffer from ridiculously cold hand. They was many a run that I came off last winter after wearing numerous pairs of gloves where my hands were still painfully cold.
I haven't got much more advice than what is offered here, but I can tell you what works for me. In extremely cold situations I have a pair of Extremities Super Inferno Mitts along with a thin pair of Merino wool liners. The Extremities have a whopping amount of Primaloft insulation which is really warm, and I find the Merino wool liners add that extra little bit of comfort I like - they're also great on there own on the not so cold days (i.e. summer!).