Originally Posted by
bkkboy
.... I do not want to spend money equipping my fold-up for touring though. After Spain I wanted to visit relatives in UK, as well as cycle Paris to London. ..
You want to do a 800 km bike tour, maybe on a folding bike. And you do not want to equip your folding bike for the trip. And you say your folding bike is not very comfortable compared to full size bike. And after the 800 km trip, you would like to do an other trip on it too. And the photo of your bike does not include a bike.
I think you have answered the questions, if you take the folding bike you are probably not going to have a very good trip.
I have not toured on my folding bike but my folding bike rides almost as well as a full sized bike, the chainstays are a bit too short for a good pannier rack in back but it would probably handle the ride ok. It is not a question of if a folding bike will do the trip, it is a question of will your folding bike be something you would enjoy for the distance.