Picking a bike for this kind of ride is a daunting process, as there as as many opinions as there are bikes. Have come to the conclusion that you ride the bike you have 🙂 For me, I rode my BMW R1150GS through the US and Canada then switched to a F800GS for Mexico, Central America, South America, NZ, Australia, and Southern Africa.
I have several Motorbikes. They have all served me well, in exploring and getting out in the world.
The 2006 BMW R1150GSA with over 100,000 riding miles around the US and Canada. Riding in 49 states on this bike.
Riding the backroads in the US. This is eastern Oregon.
Crossing a river on OBDR. Challenging on a big bike.
The F800GS, purchased in 2011 to be the primary bike I road for 2 + years throughout the world.
The Royal Enfield that I rented in Delhi to ride through the Himalayas.