From what you said, you don't own the NC750, and you are going on a long tour. You have already gotten sufficient feedback that the bike is not great for your intended use, but it can be done. How old are you and your partner? Older folks tend to not want to put up with lack of comfort, but it depends on the people.
If you are buying a bike, there is a lot to consider, its mileage, the model's reliability, its condition when you buy it, and of course it's suitability for its intended use. Don't shop alone, and see what your partner thinks about the seating. You also need room to carry clothing and gear (camping, maybe?) and power to haul that with you.