I have a Bailey Pheonix which is, I believe the same size, and layout, as the Valencia. I have a
Sunncamp 390 air porch. it runs from the back of the caravan so covers the bedroom window and the front fits between the habitation door and the front side window (so both can be opened). The picture in the link shows it covering the side window, but if you look the back is miles from the rear of the twin axle caravan.
If you shop around they can be found for a fair bit less than the link goes to. They provide a lot of extra room and all of the front and side panels can be zipped out to provide just a large sun canopy.
We are both in our late 60's and between us it takes under 5 minutes to unbag it, feed it through the awning rail, and inflate it. If you are worried about the weight simply unzip the panels to fit it, the rest retains its "shape" so the panels can be zipped back in easily.
We find it ideal for touring as its so quick and easy to erect (and having a bowed front gives a huge amount of internal space)