Before God removes the heart of stone and replaces with a heart of flesh, how free is the will of man? His thoughts are evil continually. He has no faith, and can have no faith of his own doing and therefor finds it impossible to please God. His will is bent towards sin, so much that it is said the he is a “slave to sin”. Not very free if you ask me.
But in the sense that man makes his choices based on his own desires, yes man is free. Just his “desirer” is corrupt.
I look at it this way, in a broken analogy. At 9:30 pm I’m watching a show on TV. A commercial comes on for a juicy cheeseburger. All of a sudden I make the freewill decision to get up and leave the house to go to that establishment and get a burger. I made a freewill choice...that resided inside a set of circumstances created by advertisers who have spent billions to get to know the inner me and what makes me tick.
In a similar way, God knows me so well, better than I know me, and can create the correct circumstances in my life to allow me to make the freewill decisions and yet still be subjected to His sovereignty and the working out of His will through His providence.
Pharaoh made every choice of his own freewill, and yet was directed by God to those decisions due to God knowing what it would take for Pharaoh to be hardened. To fit it in my analogy, the plagues were commercials, done by an all-knowing, always successful God.
To continue along this line of thought. I think the degree to which God influences free will decisions may be different depending on the dispensation. God being omniscient knows the outcome from the beginning, but God also knows how much He has chosen to direct the outcome.
The rebellion at the end of the Millenial Reign never made sense to me until I thought of it in terms of God leaving us to our free will and as a final example of how lost we are without His involvement in directing us. Also, it reveals how great God's mercy is because without His undeserved direction our default behavior since the fall is rebellion. Yet he seeks us out and saves us.