There are about 260M speakers around the world:
In 2010, there were 259.8 million speakers of Russian in the world: in Russia – 137.5, in the CIS and Baltic countries – 93.7, in Eastern Europe and the Balkans – 12.9, Western Europe – 7.3, Asia – 2.7, Middle East and North Africa – 1.3, Sub-Saharan Africa – 0.1, Latin America – 0.2, USA, Canada, Australia and New Zealand – 4.1.
Here is a list of countries where you encounter people speaking Russian in a good proportion.
Sure. Nothing to add here.
About 80% speak it actively, so it is safe to assume you can use your Russian while traveling there.
More than half speak it actively. You find enough opportunities to try your Russian, though in some countries people might get offended to be spoken in Russian.
About 30% or more speak it actively. Less chance than the 4 countries mentioned before but still you may be able to try it while traveling.
Fewer people speak it actively.
If you find Russia, Belarus, Kazakhstan, Ukraine, Latvia, and Moldova interesting enough, you might like to learn Russian.
Also these countries have so many ultra-beautiful women😍, arguably the best motivation in acquiring a new language🐶