Harry Kane is indeed one of the best players at Bayern Munich and now he is eagerly awaited by the English national team to contribute there. But this all depends on Harry Kane's decision. If he joins the English national team then with his age Harry Kane will have to improve his performance again and of course that will be tiring. However, when we are still at Bayern Munich, it depends on Harry Kane and how the relationship with other teams is, whether there are disputes or not. Of course it won't be too tiring anymore because Harry Kane will just continue his performance.
I agree with you Harry Kane is great player who has done very well in Bayern Munich. English national team would be lucky to have this kind of player. But if he will join national team he will have to work hard to keep playing well which might be tiring at his age. If he stays in Bayern Munich it will be easier for him because he is already a star player and has good friends in the team. It is up to Harry Kane to decide what to do and we hope he chooses to play for England and makes the fans happy. So let's see what he will choose.