In terms of numbers to cut, there are a few redundant songs here and there (the Friends of the ABC, for instance, I expect will have a significantly reduced presence). The epilogue, too, probably could stand some trimming (one song that springs to mind, even though it's a great song on its own, is "Empty Chairs at Empty Tables", which is like five minutes of Marius singing about how his friends are dead and he's sad about it; I'd probably limit the Thenardiers to only one of either "Dog Eat Dog" or "Beggar at the Feast").