He could always work on improving both his culinary and combat skills. Sigrun could teach him to fight, he could teach her to cook as he learned to do it better. They might learn to sing or play music together. He could work on improving her reading, and perhaps read the sagas to her, and some great adventure stories to demonstrate that there are things worth reading. She could recite her own tales, and I’m sure she knows whatever sagas survived in her part of Norway, and he could write them down - I’m sure that would become a best-seller. She might teach him hallingdans, and take the opportunity to improve her first aid skills. And I think Sigrun might take well to learning chess. Icelandic might be another thing she could learn, after all, generals probably need to speak it.