These days I tend to I take two of my lovely mustangs to gigs. I have a choice of five. Last time it was The Daphne Blue JMJ as the main bass with the Capri Orange Classic Vibe as backup. On Saturday the Black JMJ will get an outing, and I'll probably bring the Orange Squier again as the spare, possibly getting it out for the soundcheck.
The most basses I've taken to a gig was three when a previous band played a gig at London Zoo - Then I had an Active Jazz, a passive thunderbird and an electric upright. All three were played and the two guitarists brought (and played) seven guitars between them.