There are around 42 millions people in Ukraine. Let's see how EU countries, for example, Germany will give them work. Even if 2 millions will imigrate to EU, Germany can take some part of them.
It will not be much of a problem for the European Union nations. If they can allow the immigration of 2 million Muslims from the Middle-east, then why can't they allow the same number of Ukrainians? After-all, the Ukrainians are much more law abiding, when compared to the Muslims.