I haven't done it yet, but something I would like to do is take the Train des Pignes which runs from Nice to Dignes and is apparently very scenic. I haven't done the proper research on it yet, but I think is possible to do a day trip. In the summer they run a steam train. I think a little bit of planning is needed because there are only four trains a day, particularly since you will be there in March rather than the summer, but it could be nice day out that doesn't require a car.