A gravel pack assembly includes screen sections with a packer between them. A first screen section communicates an uphole annulus with the assembly's interior passage, and a second screen section communicates a downhole annulus with the interior passage. A housing of the packer has an internal bore communicating with the assembly's interior passage and has an internal bypass communicating external ports with one another. A first packer element disposed between the external ports restricts gravel passage at least from the uphole to the downhole annulus. A second packer element disposed downhole from a second of the external ports is independently actuated to isolate fluid passage between the uphole and downhole annulus. One or more transport tubes communicate slurry from the uphole annulus to the internal bypass once the uphole annulus is packed with gravel.