One possible reason could be to protect Teddy. Maybe there are some threats in England that Harry wants to keep Teddy away from. For example, there could be some dark wizards or dangerous magical creatures that target Teddy for some reason.
Another reason could be related to Teddy's education or development. There could be a special place or opportunity outside of England that Harry believes will be better for Teddy's growth as a wizard. He may want Teddy to experience different magical cultures and learn from diverse sources.
It might also be for a new start. Harry has had a lot of history in England, and he could be seeking a fresh beginning for both himself and Teddy. They could be looking for a place where they can be more at peace and away from the constant reminders of past traumas and battles.
The fanfiction could show their journey as a very secretive one. They might be using various disguises and spells to avoid being detected. Harry, being a well - known figure, would want to keep their departure and journey under wraps to avoid any unwanted attention or interference.
One possible reason could be to escape the danger and chaos that might be brewing in England within the wizarding world. Maybe there are dark forces targeting them specifically, and leaving is their only option for safety.
In the fanfiction, it could be that Harry is taking Teddy away to protect him from something. There might be a new threat emerging in the wizarding world, and Harry, with his experience, decides to keep Teddy safe by leaving with him. They could end up at a secret location, where Harry starts to train Teddy in advanced magic, sharing all his knowledge and skills.
One reason could be to find peace. After all the chaos and war in England, they might just want to get away from it all and start fresh somewhere else.
One possible reason could be for adventure. Hermione is a very curious character. Maybe in the fanfiction, she has heard of some mysterious magical place outside England that she just has to explore. For example, there could be a hidden library full of ancient and powerful spells that is only accessible in a far - off land.
Maybe Harry leaves England to explore the wizarding world in other countries. He could go to France to study different magic spells at Beauxbatons Academy. Or perhaps he travels to America to help the MACUSA (Magical Congress of the United States of America) deal with some dark magic threats.
One possibility is that they leave England in search of a magical place that can offer them a peaceful life. They could be tired of the constant battles and power struggles in England. They might go to a far - off land where magic is used in a different, more harmonious way. For example, they could head to some hidden island where ancient magic thrives and they can study and grow without the interference of the Ministry or dark wizards.
It could be that Harry and Susan are escaping some sort of danger in England. They leave secretly and head to France. There, they try to blend in with the local community. Harry might find work as a painter and Susan could start teaching English. Their journey would be about not only starting anew but also constantly looking over their shoulders in case the danger from England follows them.
One reason could be to escape the trauma of the war. They've been through so much in England, and leaving gives them a chance to heal in a new environment.
Maybe he's tired of the spotlight in England. In some fanfictions, he could be seeking a new start away from the prying eyes and the constant media attention that comes with being in England.