I'm just going to make a guess here, but if the Packers do end up with a new stadium, I have it will be right where Lambeau Field is today. There is too much of an investment in the projects around the stadium to remove it from that location.
Also, there' a nostalgia there, because the field itself would remain the same, just that which is around it would change.
So, what would they do? My opinion is that for a year, possibly two, they move their operations for games to Madison, and play at Camp Randall, while the new digs springs up on the site of Lambeau Field. This would make everyone happy.
But, rest assured, if you move the team from what is now considered "hallow grounds" by the majority of Packer fans, you're going to lose some, and anger almost all of them. That would include me, and I go back as far as sitting on wooden seats in old City Stadium, where Green Bay East plays.
Let's face it. John Madden was instrumental in creating the mystique of Lambeau Field, and the Packers. He's not here any longer, and there will never be anyone else like him, who could sway so much public interest. He was a special guy.