Does a two-dimensional metal survive to zero temperature?

For 2D electrons with $1/r$ Coulomb repulsion and weak short-range disorder at $r_s >> 1$, determine whether $\sigma(T \to 0) > 0$ in a finite density range $n > n_{c}$, implying a quantum phase transition at $n_{c}$ with scaling $\rho(n, T) = F(\mid n - n_{c}\mid / T^{(1/(z \nu))})$, or whether $\rho(T)$ eventually rises (logarithmically or faster) at every $n$. An answer gives the $T = 0$ phase diagram in $(n, \mathrm{disorder})$, or the crossover temperature $T*(n, \mathrm{disorder})$ below which localization appears.

Transport down to T well below $0.01 E_{\mathrm{F}}$ in samples with independently calibrated weak-localization and interaction corrections, or a controlled theory of the disordered interacting 2D electron gas at $r_s >> 1$.