It is not a law. it is a Decree.
If Congress wants some form of DACA, then all they need to do is pass a law. Right now it is an unconstitutional decree. If Ryan and the loser RINOs want it to continue, they have the power to make it happen.
Trump will probably just use DACA as a bargaining chip to get Tax Reform, The Wall and Obamacare repeal.
Give him those and the kids can stay.
The Art of the Deal.