Whatever works, in my opinion, for the situation you’re in. The standard paradigm is ||: rehearse | perform | learn new works : ||. When a classical group goes on tour, the perform function doesn’t end until the tour is over. However, I know several ensembles that pretty much play the same set every time, with a mixin of maybe 10% to 30% new rep every performance. It can evolve over time. Whatever is right for you…