There's always an implicit reasonableness requirement on these things. "Up to" isn't a wildcard that lets you do anything you want. It will protect you if you struggle to maintain top speeds during peak hours, or if a technical fault cuts speeds in half for a few days. But if you provide 1/1000th of what you claim to offer, "up to" won't stop a judge from observing that you're not really providing what you said you would.