Las Vegas would be more than doable, given that BA flew a couple of hundred miles further non-stop to LAX. Even MAN-HKG shows a great circle map distance shorter than MAN-CPT, though whether the practicality of 767s operating such a route is slightly debatable as HKG is one of those destinations that has quite a large number of pax routing via LHR, so would be more in the remit of Cathay Pacific who ought to be able to get a portion of the business traffic that would warrant a 3 weekly servce minimum.