We explore two possible Earth climate scenarios, 200 and 250 million years into the future, using knowledge of the evolution of plate tectonics, solar luminosity, and rotation rate. In one scenario, a supercontinent forms at low latitudes, whereas in the other it forms at high northerly latitudes with an antarctic subcontinent remaining at the south pole. The climates between these two end points are quite stark, with differences in mean surface temperatures approaching 4 degrees. The fractional habitability (mean surface temperatures remaining between 0$<$T$<$100$^\circ$ year round) on land is shown to differ as much as 40\% between the two simulations. These results demonstrate the need to consider alternative boundary conditions when simulating Earth-like exoplanetary climates.