I am travelling for the first time to Poland in July of 2020. I am going to be travelling independently with a guidebook and I am trying to plan how many days to spend in each place. I was planning on 3 days in Gdansk to start off my trip. Malbork Castle is high on my sightseeing list and I am wondering if Malbork would be better as a day trip from Gdansk; or worth staying overnight near the sight; or even a spend a full day-stow my luggage away train stop on my travel day from Gdansk to Warsaw. I was hoping to get as much time in or near Gdansk as I could but I would be willing to forfeit a day for a day trip to see Malbork Castle. I am not sure on distances and the frequency of trains to/from the bigger cities in Poland, so any and all advice would be greatly appreciated.
Thank you :)