Basic chemistry: If you mix ethanol and water, at room temperature, the formation of hydrogen bonds between the OH and H2O lead to production of heat. The more water you add, the more heat is formed.
So, adding hot water to ethanol, means the Viceroy becomes even hotter? If ethanol boils at 78 degrees, then what you are drinking is essentially hot water as the ethanol has already distilled off? Actually, the lower the ethanol concentration, the worse the evaporation.
Brandy should be drank
neat.
Set out to correct the world's wrongs and you will most certainly wind up adding to them.