Some say 

Next year in Jerusalem - L'Shana Haba'ah B'Yerushalayim - לשנה הבאה בירושלים‎‎

and some prefer to say:

Next year in freedom - L’Shana Haba B’heroot 

The first recorded use of this phrase was by Austrian Rabbi Isaac Tyrnau in his 15th century CE book cataloging the traditions of various Ashkenazi (Eastern European) Jewish Communities.

The phrase evokes a common theme in Jewish culture of a desire to return to a rebuilt Jerusalem, and commentators have suggested that it serves as a reminder of the experience of living in exile. 

It is usually said at the end of the seder, to remind us that even though the story ends in freedom, there are many who are not free, and the story should be carried with us after the end of Pesach. In tonight's reverse seder, we instead go from freedom into slavery, and so maybe it is insightful to think about next year at the start of our seder - our hopes and aspirations for a world which has more freedom. 

We can go around the room and say Next year in ..., filling in a hope or desire inspired by the theme of slavery, freedom and liberation.