Originally Posted by
AMDB7
I'd consider buying it at check-in if I was you - hotel gets rewarded for Ambassador members it signs up (or at least meets quota required from IHG) so you can usually use it as leverage for Ambassador benefits and a better upgrade.
I agree with this approach. I asked at the Porto IC what upgrade I would receive if I bought the Ambassador package. I was told I would get the duplex suite so happily went ahead and bought. Mind you, it was the depths of the post holiday doldrums, so it's possible that's why I was given such a nice upgrade.