The Oxfordshire is only 50 miles away from Central Northampton and just over an hour's drive by car.
A simple drive from Northampton - to reach the Oxfordshire, take the A43 Southbound and carry on to the M40. At Junction 8A, turn off on to the A418 towards Thame. Follow the A418 to the A40, then turn onto the A329, following it until your arrival at the Oxfordshire.
There are train services every hour from Northampton Station to Haddenham & Thame Parkway, changing in London. Once you arrive at the train station, a quick 10 minute taxi ride is all that stands between you and resort heaven.