The squash and apples can be roasted up to 6 hours ahead and kept, covered, at room temperature. The lentils can be refrigerated overnight; bring to room temperature before serving.
Variation: For a different presentation, you can roast the squash halves and serve the salad mounded inside.
Starchy squash and lentils call for a full-bodied white wine, like Chenin Blanc. The fruit-forwardness of the wine helps it work with the dish. Try a Chenin from California that has been blended with a bit of Viognier.