...northern Spain (with some caveats)? We will be arriving in France on June 18 and returning from Bilbao Spain on June 30, so we have 11 full days aside from the day we arrive and the day we leave.

Here are the conditions. We need to spend at least 2 full days--3 nights--each in Paris and Strasbourg France at the start, though it doesn't matter whether we start in Paris or Strasbourg, and we need to return from Bilbao Spain. We can take trains or rent cars along the way and cannot do much that isn't kid-friendly, as we'll have our 9-year old with us.

I don't know who might want to give advice with those caveats, but thanks for your responses and suggestions.