A better option this far out from the warmth of stars is our good friend methane. Methane is a liquid below 112 K (-161.5 C) and a solid at 91 K (-182.5 C). In between, you might find methane slush.
What process are you going to use to produce hydrogen from methane? You can't electrolyse methane.
Steam reforming requires water and a heat sink. Autothermal reforming requires molecular oxygen, either carbon dioxide or water, and an energy source. Partial oxidation requires oxygen. I think they all need catalysts.