  Ultracold fermionic Feshbach molecules are promising candidates for exploring
quantum matter with strong $p$-wave interactions, however, their lifetimes were
measured to be short. Here, we characterize the $p$-wave collisions of
ultracold fermionic $^{23}\mathrm{Na}^{40}\mathrm{K}$ Feshbach molecules for
different scattering lengths and temperatures. By increasing the binding energy
of the molecules, the two-body loss coefficient reduces by three orders of
magnitude leading to a second-long lifetime, 20 times longer than that of
ground-state molecules. We exploit the scaling of elastic and inelastic
collisions with the scattering length and temperature to identify a regime
where the elastic collisions dominate over the inelastic ones allowing the
molecular sample to thermalize. Our work provides a benchmark for four-body
calculations of molecular collisions and is essential for producing a
degenerate Fermi gas of Feshbach molecules.
