Philip, best way to get from the travelodge to the park is to fly along to Junc.8, turn back on yourself and come off at J9 (by the cinema/Tesco). Unfortunately although it's less than a mile in a straight line, you're stranded on the wrong side of a dual carriageway to make it easy to walk between hotel/park!
You could do a very long way round walking but it would probably takes ages and not be very safe. A taxi should cost £6-£8 at a rough guess.
Billy, it would be rude not to have a few beers! If people want to meet somewhere quite close to the venue and travelodge (where it seems most are staying), my local watering hole is very close indeed.
Or I'll come down to the park if the BBQ idea is a goer.
Ash, it's on the 17th Sept in Kettering, about 45 mins east of Birmingham from you