I have found out more about these spiders.
Not the size but the quantity...

"Trees shrouded in ghostly cocoons line the edges of a submerged farm field in the Pakistani village of Sindh, where 2010's massive floods drove
millions of spiders and possibly other insects into the trees to spin their webs.
Beginning last July, unprecedented monsoons dropped nearly ten years' worth of rainfall on Pakistan in one week, swelling the country's rivers. The water was slow to recede, creating vast pools of stagnant water across the countryside."
Full story at National Geographic