Prepare the hot roll mix according to package directions. Let rest for 5 minutes. Meanwhile, line an extra-large baking sheet with foil; grease foil. Set aside.
Divide dough in half; roll each half into a 12x8-inch rectangle. On each dough rectangle, layer 1/4 cup of the Thousand island salad dressing, half of the corned beef, half of the cheese, and half of the sauerkraut, spreading to within 1 inch of the edges. Starting from a long side, roll up each rectangle to form a loaf. Brush edges with water and press to seal.
Place loaves, seam sides down, on the prepared baking sheet. Lightly cover; let rise in a warm place for 30 minutes.
Meanwhile, preheat oven to 375 degree F. Make 4 diagonal slits, 1/4 inch deep, in the top of each loaf. Bake in preheated oven for 25 to 30 minutes or until golden. Serve with remaining 3/4 cup salad dressing. Makes 10 servings.