we do alot of repairs like that, you gotta make it stop leakin, if it keeps leakin and saggin it will eventualy fall and everything will be covered in a nasty smelling watter and dirt , gotta take everything down that was wet, take out all the wet insulation, spray all the studs and plywood with lysol to kill any mold that is growing. Hopefully the plywood diddnt soak up to much water, if it starts to buckle adn warp under the upstairs carpet ya might havet 2take it up to unless ya wanna skate park in the room. dont poke any holes in the celing untill ya ready to tear it down cause if there is any water up there its gonna pout out of the hole. Would try to get it fixed sooner then later , b4 the mold starts to grow