Is two weeks enough for France?
Two weeks is enough for a brilliant France trip, but not for the whole country. Paris plus one or two regions usually beats a route that turns every other day into a station, toll road or check-in desk.
Answer
Two weeks gives you room for a proper shape: Paris and Provence, Paris and Normandy plus Loire, Paris and Alsace plus Lyon, or Paris and the Riviera. It does not comfortably give you all of those, especially once museums, market mornings, train timing, hotel changes and meals are treated as real travel. France improves when the middle of the day is not always spent moving. Make one region the second act rather than adding several region names for balance. The trip will feel more French, not less, when the map has fewer pins.