When I was grounded during training I used to study for and sit the ground exams, thankfully I never got into a situation where the weather was flyable and I had to sit an exam. Once the exams were all sat I used to go in and talk to the instructors anyway as there was still much to learn ( there still is even though I have my PPL). I discovered that a certain area of Scotland gets fewer non flying days than the south of England, it was one reason why I travelled to Scotland to finish my PPL.