We are flying in LHR on 8/15 and planned to go to Windsor first, visiting the castle and staying at the Holiday Inn. We want to see villages in the Cotswolds on 8/16 staying overnight then driving to Chatsworth the next day. Need suggestions about car rental, best route and place to stay overnight. It can be in Cotswolds or on the way to Chatsworth. We will be staying in Chatsworth on 8/17. We haven't driven in UK before so a tad nervous.