To summarise the op is in Portugal for a 2 days work trip to do a presentation to an existing customer hoping that they will renew the licence. Bonuses are at stake including the OP manager.
The pissed colleague messaged the op before they left saying how much she was looking forward to going so she could have a break from her DC, also suggesting that they use the works money and time to get rat arsed.
When op arrived at the airport the PC had already downed 2 pints, made a bit of a scene on the plane because she couldn't have anymore alcohol. Once they had landed she bought more alcohol and continued to get more drunk, at the hotel she spent her time propping the bar up.
They went for a meal PC continued drinking while watching the match, by now so pissed she was running round screaming as the match progressed.
OP admits that they weren't really prepared for the meeting, the PC needed to get some slides ready but has failed to do so, OP had no choice but to ask a colleague back here in the UK to send some slides but they are just generic ones not the ones that are tailored to the client like the ones PC was supposed to do.
PC came to the OP room early this morning all apologetic, you have tried to go through the presentation PC maybe able to just add a small amount of information during the meeting.
The meeting is at 10 am the PC got to her room around 1 am. The colleague back here that had to help has informed your manager, who has been in touch and is being supportive.
Good luck OP, you will now be doing the presentation so fingers crossed it goes well.