There is no good answer. No matter how 'hot' someone may want their drink it's still ~155 degrees or you'll burn the milk. And after 15-20 minutes, they can't possibly be a good representation of your drinks. I would either limit to coffee only because that alsmost always needs to cool before people can drink it, or you can have a contract with the main businesses you deliver to and use some cool thermal cups (you'd have to pick them up next delivery), or you can offer iced drinks only and negate that whole thing.
All you can do is 'guaranteed awesomely fresh when made'. Other than that you'd either have to lie or promote selling bad drinks. neither is good. But don't burn your milk... there really is no such thing as "super hot" there's a correct temp, and lower for kids... there's not a hotter one.
Best of luck. :?