How much stuff are you likely to be carrying?
This is my 660, a thousand (tarmac) miles from home. It was fine, even at 80mph on the motorways. Probably worth upgrading the shock, as the stocker was still quite saggy even at full preload.
Now you've got about 35kg of bodyweight on me, but equally, if I was actually expecting to ride dirt with the luggage fitted on that trip ^ I'd have packed a lot lighter, which offsets it a bit.
How much of your planned trip are you likely to even have the option of riding at highway speed?