Any move back to 'pre convention' polling would still give Clinton an Obama 2012 style victory.
Really if you look at the current polling averages, Clinton is back to her post-primary/pre-Commey numbers of around a 6-5% lead. Pre-convention numbers were not that great for Clinton, she was around 3-4%.
As long as we keep hearing stories of GOP officials in NC and PA freaking out about their own internal polls showing double digit deficits and RNC rumblings of having congressional running ads that say they will be a check on a President Clinton, I'm not worried.