Set up the same way, but instead of Anthony Hopkins banishing Thor to Earth, he should have sent the hammer to Earth and locked Thor up in jail on Asgard.
Then the Ice Giants infiltrate Asgard again, this time nearly fatally wounding Anthony Hopkins. Loki tells Thor that their father is dying and that Thor needs to go to Earth to find the mystical something or other that will be a cure.
Thor goes to Earth, but his motivation is more to get his hammer than finding the cure (because he has yet to grow and think selflessly). Loki shuts down the portal behind him, tricking him and insuring that no one on Asgard can stop his overthrow. Also get rid of Thor’s backup dancers, the ones who look like the Black Eyed Peas, because they serve no purpose.
While on Earth, Thor runs into Natalie Portman; she’s the only scientist who believes in the wormholes, so she’s the only one who can get Thor back.
Meanwhile SHIELD is still trying to figure out what the hammer is doing stuck in the ground. Loki catches wind that Natalie Portman is nearing completion on the Wormholinator and sends the giant metal robot to destroy Earth. Thor (at half strength) summons the courage to save the next town set to be destroyed. He gets his hammer back as Natalie Portman figures out how to send Thor back. Thor seemingly kills the giant metal robot.
Final fight happens on the rainbow bridge with Thor against Loki and a horde of ice giants. Thor's ace up the sleeve is the giant metal robot, who is reprogrammed and kills Loki. With Loki dead, Anthony Hopkins awakens.