That would actually an optimistic scenario. More pessimistic one would be if you notice Putin got approval to use Russian military in Ukraine, not just in Crimea. Which means he can also use it it Kharkov, Donetsk, Lugansk and other places where there is a majority Russian population. And try to split Ukraine along language-ethnic lines and destroy it as an independent state as a punishment for defying them. Note that any success of new Ukrainian powers spells trouble for Putin, as it means one can defeat the authoritarian rulers and succeed, while the official position is that the authoritarian rule is the only defense against chaos. So Putin would be very invested in causing the said chaos in Ukraine, both as a revenge, as means of control and to support the idea that his rule must be strong - otherwise see what happened to Ukrainians. So just having Crimea separate, as I say, would not be the worst yet.