Where do you think GT is ranked going into the Miami game? To get to 12/13 after Miami, we'd need to be Top 20 going in. No way UNC + Poly gets us to top 20.
It's questionable. VT is still regarded favorably (getting some votes in the polls), so beating them would definitely get us a boost.
It really depends more on the other teams losing than us winning. If no teams in the top 25 lose there isn't much room to move up. Of the teams ahead of us, Texas Tech isn't losing (Tex St and Kansas), Wisconsin has Ohio State (assume loss), Arizona St has Stanford and USC (at least one loss), Notre Dame has Oklahoma (assume that's a loss), Ole Miss has Alabama (assume a loss), Baylor has La Monroe and a bye (assume both wins), UF has Tenn and Kentucky (wins), Northwestern has Main and a bye, and Washington has Idaho St and Arizona.
So we could conceivably jump Wisconsin, Arizona State, Notre Dame, and Ole Miss. By my calculations, that puts us at 22 (ignoring the teams also receiving votes, who I think we can straight up jump with both wins). Also possible we jump a Texas Tech or Baylor team who hasn't played anyone. At best that is 19. More realistically I think you are looking at 21 (assuming we win both games).
The big jump would come after beating Miami on the road. Getting ahead of myself, we would catapult to top 15, probably number 12 there.