I am also an avid concert goer, and I usually had 3-5 drinks during the show. Very tipsy to hammered.
Saw Alt-J sober, it was amazing, but I did get a slight trigger every time I walked by the bar. But then I reminded myself I didn't need to budget 15 minutes standing in that line for a crappy overpriced concert drink. Went to the other bar with no line and got a ginger ale instead.
LOVE Fleet Foxes, really loved the album with Father John Misty. Sounds like way big fun!