So, O'Brien didn't really work in a meatpacking plant the summer before he went to Vietnam, and he didn't go up to the Canadian border to try to get away from the war and then chicken out and return home. It's a symbol for his mental state at the time. He can't get the nightmarish idea of slaughter out of his head – it's all he can think about – and so he thinks about running away. He's on the edge. Eventually, though, he backs off the edge. He doesn't go to Canada.
Elroy Berdahl is an important symbol in all of this, as O'Brien explicitly states:
He was the true audience. He was a witness, like God, or like the gods, who look on in absolute silence as we live our lives, as we make our choices or fail to make them. (On the Rainy River.74)
If Berdahl is God (or your deity of choice – atheists, feel free to use the universe as a stand-in), then God is ambivalent here. He doesn't push Tim to make one choice or another, and he doesn't judge Tim either way. He's simply there, watching, and his presence is felt.