  Isolated black holes (BHs) and neutron stars (NSs) are largely undetectable
across the electromagnetic spectrum. For this reason, our only real prospect of
observing these isolated compact remnants is via microlensing; a feat recently
performed for the first time. However, characterisation of the microlensing
events caused by BHs and NSs is still in its infancy. In this work, we perform
N-body simulations to explore the frequency and physical characteristics of
microlensing events across the entire sky. Our simulations find that every year
we can expect $88_{-6}^{+6}$ BH, $6.8_{-1.6}^{+1.7}$ NS and $20^{+30}_{-20}$
stellar microlensing events which cause an astrometric shift larger than 2~mas.
Similarly, we can expect $21_{-3}^{+3}$ BH, $18_{-3}^{+3}$ NS and
$7500_{-500}^{+500}$ stellar microlensing events which cause a bump magnitude
larger than 1~mag. Leveraging a more comprehensive dynamical model than prior
work, we predict the fraction of microlensing events caused by BHs as a
function of Einstein time to be smaller than previously thought. Comparison of
our microlensing simulations to events in Gaia finds good agreement. Finally,
we predict that in the combination of Gaia and GaiaNIR data there will be
$14700_{-900}^{+600}$ BH and $1600_{-200}^{+300}$ NS events creating a centroid
shift larger than 1~mas and $330_{-120}^{+100}$ BH and $310_{-100}^{+110}$ NS
events causing bump magnitudes $> 1$. Of these, $<10$ BH and $5_{-5}^{+10}$ NS
events should be detectable using current analysis techniques. These results
inform future astrometric mission design, such as GaiaNIR, as they indicate
that, compared to stellar events, there are fewer observable BH events than
previously thought.
