In a 3- to 4-quart pan, combine Merlot or other dry red wine, tawny Port, and orange juice. Bring to a boil over high heat and stir occasionally until reduced to 1 1/4 cups, 12 to 15 minutes. Meanwhile, in a small bowl, combine 1/4 cup hot water and demi-glace (see notes).
Crumble enough of the Gingerbread Wedges or gingersnaps to make 2/3 cup. Add gingerbread and demi-glace mixture to wine mixture; let stand until gingerbread has softened, 3 to 5 minutes. Pour into a blender. Add whipping cream and whirl until smooth. Return to pan.
Stir over low heat until hot. Whisk in butter until blended and smooth. Add salt to taste.