I can't see why Fang would want to go anywhere and rebuild a D yet again at his age. He must know the clock is ticking and by no means is he dumb. He sees AR is in the twilight of his career, and Trubs is just starting his. I really don't see him leaving now that Fox is gone. Unless of course he has a problem with Pace or the owners.
These guys are his boys now so I see him staying unless a dream HC position opens up with a pretty good base group of guys on the roster.
I think it may all come down to what Pace can offer him and if he's serious about keeping him then he should make him a very serious offer before he even talks to others provided he believes it offers more money and greater authority than anyone else can offer.
The alternative would be a handshake agreement that Vic will come back to him with the offers he's gotten and give Pace an opportunity to respond to them. I don't believe that would include the HC job but no one can say for certain right now where they left things.
I would be very surprised in 2018 if any coach had that kind of emotional attachment to any job Bob. Loyalty in the NFL could probably be represented by $$$$ and a GFY if the deal isn't right. Vic is only 59. He could coach for a very long time still. Dick Lebeau is 80 and he's the Tennessee DC.