Just enjoy the Coltwolds, its on your doorstep. We have family in Bourton On The Water and go every year during September and am still finding more and more to do each time we go.
If you like history, there's Sudeley Castle and Berkeley Castle (to mention just 2).
If you like birds of prey, the Cotswold Falconry Centre is a brilliant and always has a good flying display.
There's some wonderful places to visit, Cheltenham itself is lovely, Stow On The Wold, Tewkesbury, Moreton In Marsh, Lower Slaughter and of course Bourton which also has a great little motoring museum.
There's probably something going on at the Racecourse too.
My dad is a member of the Vintage Sports-Car Club and there is the Prescott Sports Hill Climb this weekend, only a couple of miles from Cheltenham too. Always some incredible pre war motor about inc Bentleys, Astons etc and it doesn't cost a lot and always a good day out. Check out the vscc.co.uk website for details.