I'm thinking about a number of options:
1. Scrapping the flight from Paris to London and taking Eurostar ($140 cancellation fee...ouch)
2. Taking the Paris to London leg the day before and spending one last night in London, maybe near the Tower so I'm not too far from LCY, and doing some kind of activity that night/morning. (No change fee when done on-line, and there is plenty of availability). (Open to suggestions on area in which to stay where there is something to actually do...so not the Docklands.)
3. Waiting to see if AA ever loads any pairs of J award seats on their CDG-JFK route. (Unlikely to get two seats...very stingy route for awards.)