The polls of polls I saw were much closer than that as indicated in the graph, somewhere between slight lead for Leave to the Telegraph's +2 for Remain. Margins of error for referendums should be high as turnout and voting patterns are a lot harder to predict than general elections.
Primaries also have higher margins of error than general elections but for all the talk of "shy" Trump voters he actually underperformed his poll forcasts on the way to the nomination although hard to know whether that will also be true in the general.
The last poll I saw that asked the enthusiasm question had a big change after the debate with both candidates equal but haven't seen more recent polling on that question.
https://today.yougov.com/news/2016/10/06/clintons-lead-persists-democrats-enthusiasm-her-ca/
Trump's job this debate was to try to persuade some of the undecided/thired party voters, or even better Hillary supporters, to change their mind. Personally I couldn't see anything in last nights debate that would have done that, or at least nothing that would not have been outweighed by the election rigging/bad hombre/nasty woman remarks. Usually takes a few days for the impact of debates to reflect in polls, Monday's polls will be interesting.
But over 2 million votes have already been cast and he has an awful lot of ground in the electoral college to make up.