In reply to Dom Whillans: 3 days off-road sounds great.
I spent a week biking (mostly on road with some trails) and swore I'd never, ever take a rucksack again. Came back with black and bleeding shoulders. Yeah, I was young and pleased just to get away! Hence my pannier recommendation.
I have seen guys using "Bob" trailers off-road. That looked the best way to do it. They were doing some pretty serious stuff as well.
Sounds like a great trip. I'd take the Kona for simplicity.