Originally Posted by at240

Not trying to be difficult, but -- sorry -- no! You can't expect to book someone into a lower cabin and then guest them into a higher cabin for the entire flight. Besides, in CW you don't have a buddy seat, so it would only take a flick of the captain's wrist to switch on the seatbelt sign and ruin your plan.

I think the crew would be pretty wise to this sort of game (and rightly so).

I agree with what sunrisegirl and henkybaby have said.