  We use finite temperature strong coupling expansions to calculate
thermodynamic properties of the Honeycomb-lattice SU(4) Hubbard model. We
present numerical results for various properties including chemical potential,
compressibility, entropy and specific heat as a function of temperature and
density at several $U/t$ values. We study the onset of charge incompressibility
and Mott gaps as the temperature is lowered at integer densities. In the
incompressible Mott regime, the expansions are recast into a high temperature
expansion for a generalized spin model with SU(4) symmetry, which is then used
to study the convergence of strong coupling expansions in t/U. We discuss
lessons that can be drawn from high temperature properties of a simple Hubbard
model regarding Twisted Bilayer Graphene (TBG) and other magic-angle flat-band
systems.
