2 technical questions on stationary heating

Dear standing heaters. Did I have the stand heater unlocked for the D5 at Rossi in Desenzano and ask myself now, since the operating instructions do not say: 1. How warm does it heat up at all? Logically, it would seem to me: up to the temperature set in the climate automation. Is that right? Or does it just heats through, without regard to limit temperatures? 2. Does the “preheating” of the interior at extreme minus temperatures possibly also have a preheating effect for the engine? So you do him something good in the winter? (* puzzle*) Who shares his knowledge with me in this respect? Thanks already in advance. wgr