I did forget to write that among the touring type bikes Machka and I have ridden on randonnees are tandems. Might seem light to take, but they have their own challenges and there is a whole new way to ride a longer bike with another person on board. Especially when speed down a twist downhill has to be moderated... and there is strong headwind to get into.
One of the bikes was borrowed and we did four or five randonnees. The second bike we bought brand new and still have, but haven't ridden in quite a long time. I am trying to fit a rear disc brake so that downhill issue isn't so challenging to control.
As touring bikes, both could be set up that way, but the ability to carry enough to cover both needs can be a little challenging, too.