ViaMichelin.com gives three suggested routes for that drive (I'm assuming you'll have a car). By far the fastest routes you through Italy. I'm guessing the two French routes are more mountainous and most likely more scenic, but I do not know for sure. On the off-chance you prefer to stay in France, I can recommend a stop in the little medieval town of Entrevaux, which is between Villefranche-sur-Mer and Digne-les-Bains.
Both French routes are estimated at 7-1/2 hours or more without stops, traffic delays, etc. Even the Italian route is estimated to involve almost 5 hours of pure driving time, and the last bit of it might be challenging; it runs through Aosta. I wonder how tiring it would be to attempt this drive in one day.