This calculator has us being overtaken by Argentina if they win by more than 15 (we'd still be ahead of France, but Argentina jump past us and France)
https://rawling.github.io/WR (World Rugby)-calc/?d=2018-09-17&f=1:39,38,20,15;40,37,15,20;39,37,15,20;40,38,30,10
I think we go back to 5th if we can beat...