  We investigate the striking absence of strong localisation observed in
mesoscopic two-dimensional electron gases (2DEGs) (Baenninger et al 2008 Phys.
Rev. Lett. 100 1016805, Backes et al 2015 Phys. Rev. B 92 235427) even when
their resistivity $\rho >> h/e^2$. In particular, we try to understand whether
this phenomenon originates in quantum many-body effects, or simply percolative
transport through a network of electron puddles. To test the latter scenario,
we measure the low temperature (low-$T$) transport properties of long and
narrow 2DEG devices in which percolation effects should be heavily suppressed
in favour of Coulomb blockade. Strikingly we find no indication of Coulomb
blockade and that the high-$\rho$, low-$T$ transport is exactly similar to that
previously reported in mesoscopic 2DEGs with different geometries. Remarkably,
we are able to induce a `metal'-insulator transition (MIT) by applying a
perpendicular magnetic field $B$. We present a picture within which these
observations fit into the more conventional framework of the 2D MIT.
