If you haven't yet, do yourself a favor and watch "Long Way Round". Amazing documentary series the BBC aired of Ewan McGregor and his buddy and fellow actor Charley as they travel east across Europe and the US. 20,000 mile trip through the countries you're planning.
In 2004 Ewan and Charley embarked on an epic Long Way Round challenge, to bike 20,000-miles, cross 12 countries and 19 time zones in just 115 days. Riding their BMW GS R1200s, they crossed Europe, Ukraine, Russia, Kazakhstan and Mongolia to ride the Road of Bones through Siberia, over to Alaska, through Canada, North America and finished in New York. The Long Way Round journey would challenge their view of the world and also test their physical endurance.
You can find it pretty easily on Amazon, or their website here