Hey there! We are planning a DLP trip for November, very similar to your situation. We're in Florida, and none of us have been to DLP, though I have been to both Paris and London. My husband and daughter, however, have never been to Europe.
If it were just me, I would completely skip Paris and go straight for London. But I really don't want my family to miss out on some really neat sites in Paris just because I personally don't care for the city. So as a compromise, I think we will be taking a day trip into the city from DLP on a tour where you can get on and off the shuttle as you please. That way, if there is something specific hubby wants to see, or if my daughter is getting antsy and needs some play time, we can adjust.
However, if you are very much into culture, you'll likely want to visit the Louvre and a myriad other museums in Paris, which could take you a day to see everything by itself. Lines for the Eiffel Tower can get ridiculously long, and you'll definitely want time to stroll the Champs Elysees, see Notre Dame Cathedral, etc. So I would leave at least two (2) days for Paris if not three (3) if you really want time at the museums, etc.
Hope that helps!