  Simple SO(10) Higgs models with the adjoint representation triggering the
grand-unified symmetry breaking, discarded a long ago due to inherent
tree-level tachyonic instabilities in the physically interesting scenarios,
have been recently brought back to life by quantum effects. In this work we
focus on the variant with 45_H+126_H in the Higgs sector and show that there
are several regions in the parameter space of this model that can support
stable unifying configurations with the B-L breaking scale as high as 10^14
GeV, well above the previous generic estimates based on the minimal survival
hypothesis. This admits for a renormalizable implementation of the canonical
seesaw and makes the simplest potentially realistic scenario of this kind a
good candidate for a minimal SO(10) grand unification. Last, but not least,
this setting is likely to be extensively testable at future large-volume
facilities such as Hyper-Kamiokande.
