Understanding extreme space weather events in terms of the geospace response is a critical step towards protecting vulnerable technological infrastructure. This is particularly relevant for the effects of geomagnetically induced currents (GICs) on ground-based power grids, which can be approximated by examining the rate of change of the surface magnetic field, $dB/dt$. In a previous study, \citet{Tsurutani2014} created estimates for a perfect, isolated interplanetary coronal mass ejection (ICME) and performed a simple calculation for the response of geospace, including $dB/dt$. In this study, the estimates of \citet{Tsurutani2014} are used to drive a coupled magnetohydrodynamic (MHD)-ring current-ionosphere model of geospace to obtain more detailed and physically accurate estimates of the geospace response to such an ICME. The sudden impulse phase is examined; calculations of surface $dB/dt$, Dst index, and day side magnetopause compression are compared to the less sophisticated estimations of \citet{Tsurutani2014}. It is found that while the previous study yielded similar estimates for Dst rise and magnetopause compression, $dB/dt$ estimates are as much as an order of magnitude lower than the results obtained via physics-based modeling. This work shows that $dB/dt$ values in excess of 30$nT/s$ are found as low as 40$^{\circ}$ magnetic latitude. It is also shown that the direction of the interplanetary magnetic field plays a critical role: under southward IMF conditions, magnetopause erosion combines with strong region 1 Birkeland currents to intensify the $dB/dt$ response. The values obtained here surpass those found in real-world events and sets the bar for the upper threshold of extreme GIC activity at Earth.