https://winnebagoind.com/products/cl...tseer/overview
that says it's a "one piece fiberglass roof".
Which means it is repaired just like any other fiberglass part.
Take the stuff off the roof area.
Cut the broken edges to remove fibers that keep it from closing up flat.
Remove the interior ceiling liner and roof insulation.
Reglass the area, ideally from the bottom to add thickness / structure without affecting the top cosmetics.
Reglass the top area post sanding it rough.
Sand the new exterior glass smooth,
Body plastic and sand till very smooth and near pock free.
Spot putty till perfectly smooth
Sand
Clean
Mask
Prime and paint.
A picture would be very helpful to get any more info that isn't general.
Very likely fixable and NOT totaled. But a picture would sure help.