I certainly wouldn't. You're topping out as the third-best program in the second-toughest division at Tennessee, versus the second-best program in the toughest division at Penn State. And I think there are a lot of people in the business who also don't - especially not in their current state.
But they're almost certainly going to pay more - a few million more, most likely. And Tennessee (whether it was benefited by extra benefits or not) has certainly shown over the past few years that it's easier to get top-tier recruiting classes there than it is here. If a totally unlikeable goober like Jeremy Pruitt can sell the SEC en route to top tier recruiting classes, logic would suggest that a coach like James Franklin can do better than that. At the end of the day, being an SEC school unlocks talent in SEC states more than being a B1G school does (if you aren't Ohio State). So I can see a coach like Franklin being attractive, for sure.
He's almost certainly not taking the job, and if there were discussions between Franklin and Tennessee, I doubt that they got much further than "hey Trace, would your guy pick up the phone if we were willing to pay $10M?" and Trace said, "who wouldn't pick up the phone for $10M?"