If it was me going to Duxford I would look to stay in or around Cambridge and go in to Duxford on the Park and Ride.
Traffic queues to get in/ out of Duxford can be lengthy and the bus by-passes all these ( it was free when we went last year).
If you stop in Cambridge make sure you find accommodation with car parking as public car parking can be horrendously expensive.
Hope you have a good time
