For trips that long I would go with something bigger. I loved my KLR, but 650-750 is small for long runs IMO.
Honestly a cruiser is what you need for trips like that. Honda, HD, Kawasaki, Yamaha, BMW...I don’t get into those arguments...they all make good bikes. Pick what’s best for YOUR situation.
I second the idea that if you’re going to do mostly highway, the enduro isn’t what you’re after. The seat, for one thing, is not conducive to any long trips and you’ll be sorry.