The numbers from 2010 presidential election in Ukraine show that Yanukovich won by about 500,000 votes, and it almost exactly matches his margin of victory in Crimea. So, yes, if we extrapolate them into future polls, you may be correct. But my guess is that there is a large group of swing voters there that can lean either way for reasons other than pure ethnic background or language preferences. At the end of the day, their current economic conditions and expectations affect their choice, as well as some intangibles, like sense of security, protection of civil rights, etc. Today, though, emotions fly high in Ukraine, and it has a profound effect on the parliaments in Kiev, Simferopol and Moscow.

Militarily, Ukraine stands no chance to defend itself against Russia, should the latter decide to attack. The question is if Putin really wants to go all-in. I'm sure his administration is very busy now weighing pros and contras. Among other parameters, they need to be clear as to how much Russia will have to spend to "bribe" eastern Ukraine into obedience in the long term.