Yes he does like to party but he is very professional when he works and usually avoids drinking and parties when he is shooting the next day.
Najin is right. He's always been the consummate professional when he's working. Even if he's just in training for a role. I would imagine he would have communicated with them by text or phone call, even arranged to have drinks privately at a hotel bar, but first, he's not exactly enamored of the Hollywood scene and second, those parties are monstrously huge and very difficult to actually visit with people to any extent. The only way he goes to those things are if he's had to participate in the awards by being a presenter or by being nominated or if he's contractually obligated to attend to support some specific project or gets suckered in to it by his daughters or someone in his inner circle. Now, the ones that are pure fun like the Brits or the Scream Awards are something entirely different. Those tend to poke fun at the staid, traditional awards shows and parties.