Yes, you'd definitely be better off with a car. Yorkshire is awesome (obviously!) but the Lake District (especially around Windermere and Ambleside) is probably the best place to stay! Scotland is pretty spectacular too if you have a car!
That said, even if you don't have a car we've had couples fly over from abroad for shoots in the Lake District and they have taken a train from London to Windermere without any problems. London to Leeds is only about £20 on the train but Yorkshire's difficult without a car!
Great, thanks! Maybe we bring a car in the ferry.