What about Pink Pet? Mine is tip hardy in Z6. Grafted and planted in 2018 it's is at least 4' high and is constantly in bloom with small pretty flowers. A deep dark red that would be hardy in Z is AC Navy Lady. It also makes a great looking bush. Two or three would fill the space. Are you going to repeat the same on the other side or maybe use a climber in a similar colour to go up the banisters and end column? If you are and chose NL Red Cascade climber has a similar dark colour. Jean LaJoie would be pretty as a pink climber although I've read there exist a climbing pink pet. None of these are the most fragrant but PP has a light clove scent that wafts for me. If you are looking for scent perhaps Marie Pavie . I love this rose also. If you want to get fancy you could mix it with its pink sport Marie Daley.
