With the government shut down , how early should I be there. ( international flight)

No change. The government shut down is a joke

Won't hurt to reach 180 min before the departure.

2 hours before is the suggested advance arrival time. I flew last Thursday internationally and did not notice any delay or issues and cleared security in less than 30 minutes.

I didn't notice any change. But if you want to be safe, be there 30 minutes earlier than usual.