[Grampa]

I have to agree with Chuck

If it was me - and funds weren't an issue I would attempt a ride to Alaska on a newer model probably a model that was less than 10yrs old, so there would be ample spare parts available should you require one.

On that trip especially, I would try to eliminate as many potential problems well before you depart. I too would recommend some type of dual sport bike because of the iffy weather & road conditions you may encounter. But that is certainly not a prerequisite for the trip.
What ever you do, I wait with anticipation to hear all about your trip.