Plenty of little things to amuse them that wont take up a lot of room. Tennis balls are great and take colouring in books and pencils etc because if the weather is hot you don't want them outside all the time. Do you have a baby bath at all still? Might be an idea to take that too to make washing them easier as you wont have a lot of water available for bathing and you will need to make the most of every drop of water(unless there are amenities where you are going with showers etc).

ETA - warm clothes for the kids to sleep in at night because it is surprising at just how cold it can get at night and you don't want to be caught out.