Constantinople, what you're proposing is just so politically and militarily unrealistic... if Nicholas had followed the game plan you've outlined (and I doubt his general staff would have stood for it for one second), he would have been overthrown by his own military and the urban populace would have taken to rioting in the streets. Meanwhile the peasantry would be welcoming the German troops with bread and salt in most places - not only in Poland, the Baltic States, Ukraine, and Belorussia, but even in Russia proper. The Russian peasantry didn't give a damn about Russia, most of them didn't even understand the concept of "Russia" - they were still living in the 17th century, when peasants across Europe thought of themselves as "belonging" to a particular province or region, but had no clue when it came to the concepts of nation or state. No, my old history professor was right, given such a scenario, Russia even if it managed to maintain a degree of autonomy would have emerged half its size and little more than a German satellite.