EDIT: I guess I didn't mean "what if Google was forced to do this overnight?", but rather I meant more like "couldn't Google make this backfire by doing this overnight?".
Good luck finding somewhere else you can reimport that and continue working. It might as well be an encrypted blob.
Legally speaking, I'm sure there's plenty of ways the EU can force Google to do things it currently does not want to do.
I'd say the EU has lots of negotional angles currently to win things from Google. That is kind of what you get when you have more or less universal legislation power over 40% or so of the world's purchasing power (please correct me, I just bullshitted that guess). And that, alas, was also a large part of why the EU was born. So now we'll will reap the benefits.
If I could say anything to our EU negotiators in this case, it would be: stay brave.
Europe GDP is 20.9 Trillion USD. The world GDP is 107 Trillion USD. So Europe is only 20% of the world GDP.
But one can make the argument that EU citizens are better connected and spend more on digital goods. Though I'd be surprised if it drives more than 30% of Google revenue.
EMEA, APAC, Other Americas, US
Out of this, in 2017, EMEA was 32.5% of total revenue, based on numbers from page 33 of https://abc.xyz/investor/pdf/20171231_alphabet_10K.pdf.
My bullshit-guess is that out of those 32.5 percent units, EU/EES was responsible for about 31 units or so, and the rest 1.5 was from the middle east and africa. (Reasoning: the ME certainly has money, but no population to speak of. Africa has lots of people but besides relatively tiny South Africa very little revenue for Google.)
So yeah, the EU has a pretty powerful hammer.