I have published a trip report on Québec City which our family visited for three days as part of a road trip in Québec several years ago. This is a wonderful city to visit for families with kids of all ages. The city is compact and easy to see on foot, there are many historical attractions to visit and it exposes kids to a culture that is quite European. It also affords an excellent opportunity for everyone to put their classroom French to practical use. We visited during the height of the summer season when the old city is teeming with tourists soaking up the sun and people-watching at outdoor cafés but I'm sure that a visit during La Carnaval de Québec (Québec's Winter Carnival) would be just as memorable.