My take
Hot wash / Warm rinse = Redundant
Warm Wash / Warm Rinse = Redundant
Hot Wash / Cold Rinse = Whites, Towels, Bed linens, underwear & Kitchen linens/cleaning cloths etc
Warm Wash / Cold Rinse = Everyday clothes, Delicates, Wool/Silk, Outerwear
Cold Wash / Cold Rinse = Maybe in rare...