It can be done, just do it as early as possible to avoid problems. But if I were you I wouldn't. We had originally booked POFQ for our most recent trip and uprgraded to WL and were greatly disappointed. Yes, the lobby is cool but the rooms are pretty much the same size as the moderates. If you still want to upgrade it's woth it to splurge for a REAL deluxe, not WL or AKL. For a little bit more moolah you get a much bigger room, and more amenities. I recommend one of the monorail hotels. If you don't want to spend that much, you're better off just staying at POR. Hope that helps!