We can choose Heaven at any time, but we must choose it with our brother. This idea is central to the Course: this particular pathway requires that we not walk alone. Moreover, the Course clearly says that we are not victims of the world, nor are we strangers within it. All of our fellow travelers are brothers on a common pathway. And we will choose together or not at all. If we choose not at all, we can never “make” Heaven in illusions; we can only stay in the hell and misery of this world.
The Course asserts that the time of our choosing of Heaven is in our hands. Until we use our power of choice to choose otherwise, we are left in this world, seemingly (to us) as victims, but, thankfully, this state of affairs need not remain with us.