A variable temperature-selected ion flow drift tube (VT-SIFDT) has been used to measure the mobilities of NH4+(NH3)(n) clusters drifting in He. The mobilities have been measured for n=0-2 at 298 K, n=0-3 at 200 K, and n=0-5 at 100 K, marking the first mobilities experiments for these clusters below room temperature. The reduced mobilities measured at 298 K are compared to the previous SIFDT results of Krishnamurthy [J. Chem. Phys. 106, 530 (1997)] for n=0-2. While the current results compare quite favorably for n=0-2, there is a discrepancy for n=3 which is addressed by current 100 K and 200 K data where these species are thermally stable. The trends in the mobilities from 100 K to 298 K as a function of E/N and effective temperature reveal that the repulsive part of the He-NH4+(NH3)(n) interaction potential is sampled predominantly for n=1-5. However, the attractive part of the potential is accessed at the lowest temperatures for He-NH4+.