We consider " super no-scale models " in the framework of the heterotic string, where the N = 4, 2, 1 → 0 spontaneous breaking of supersymmetry is induced by geometrical fluxes realizing a stringy Scherk– Schwarz perturbative mechanism. Classically, these backgrounds are characterized by a boson/fermion degeneracy at the massless level, even if supersymmetry is broken. At the 1-loop level, the vacuum energy is exponentially suppressed, provided the supersymmetry breaking scale is small, m 3/2 M string. We show that the " super no-scale string models " under consideration are free of Hagedorn-like tachyonic singularities, even when the supersymmetry breaking scale is large, m 3/2 M string. The vacuum energy decreases monotonically and converges exponentially to zero, when m 3/2 varies from M string to 0. We also show that all Wilson lines associated to asymptotically free gauge symmetries are dynamically stabilized by the 1-loop effective potential, while those corresponding to non-asymptotically free gauge groups lead to instabilities and condense. The Wilson lines of the conformal gauge symmetries remain massless. When stable , the stringy super no-scale models admit low energy effective actions, where decoupling gravity yields theories in flat spacetime, with softly broken supersymmetry.