I'm outside Wisconsin, and I watched their stream last year...

Per Zach Kruse, Packers Wire (USA Today), it's nationwide. From the link I posted below:

"In the recent past, the Packers have only made the event available through the limited-area television broadcast, mostly in fear of compromising a competitive advantage with a full broadcast of a training camp practice. Now, Packers fans from across the country will get an opportunity to see Family Night without needing to find an alternate online stream."

I remember last year when the Packers announced the streaming option, it was stated that the stream was intended for "out of state" fans. If there is any geo-locking involved, I suspect it's locked in such a way that anyone in a media market served by their TV broadcast can't view the stream. But even that, I doubt...