  Spatially confined solutions of traveling convection rolls are determined
numerically for binary mixtures like ethanol-water. The appropriate field
equations are solved in a vertical crossection of the rolls perpendicular to
their axes subject to realistic horizontal boundary conditions. The localized
convective states are stably and robustly sustained by strongly nonlinear
mixing and complex flow-induced concentration redistribution. We elucidate how
this enables their existence for strongly negative separation ratios at small
subcritical heating rates below the saddle-node of extended traveling
convection rolls where the quiescent fluid is strongly stable.
