Are you just going for the race day on Sunday or for the whole weekend?
I grabbed my programme for last year and the timetable for Sunday was as follows:
7:00 Closing of track to road traffic
09:45 – 10:15 Porsche Mobil 1 Supercup Race
11:10 – 11.55 Formula Renault 3.5 Race
12:30 F1 Drivers Track Parade
14:00 Grand Prix de Monaco
19:00 Opening of track to road traffic
So…. …a pretty busy and full day – it’s worth remembering that it’s not just F1 – you’ll probably do well with drinks following the Grand Prix at one of the Monaco bars. You should have no problem there!
Hope that helps! :)