expire visa before travel to us

We have received American visa in 16 Agu 2016 Actually the visa is available until 12 feb2017 So, we arranged to travel to US for landing in01febb 2017 and already bought the flight tickets for myself and my family from iran to us. But unfortunately we have heard about some overwhelming news about a new temporary law in order to Iranians enterance restriction.
As you probably can guess I am really confused and do not know whether this is applicable for me and my family or not.
Now, I am searching for a proper solution. Would you please guide me?
Is it possible to expand the expire date of the visa, then maybe there would be some modification in near future.
I am looking forward to hearing from you.

by best regard