I am looking for a faithful translation of constructions like the following:
It will be a challenge to keep this collaboration alive, let alone productive.
The best I can think of is
Va a ser un desafío [reto?] mantener esta colaboración viva, ni hablar de productiva.
Is this understandable (let alone good!) Spanish?
Searching online for translations of the "let alone" construct in English, I often come across forms based on más or menos, usually qualified with an intensifying adverb like mucho, aún, or todavía. For example, using such a form, the above sentence could be translated as:
Va a ser un desafío mantener esta colaboración viva, y aún más [lo será] el mantenerla productiva.
This definitely is an adequate, workmanlike translation.
It is, nevertheless, charmless and "square". What is lost in this translation can be easily seen by translating it back to English as given, and comparing the two English versions:
It will be a challenge to keep this collaboration alive, and even more so [will be] to keep it productive.
I am hoping to find a translation to Spanish that avoids such dullness.