OK just done the maths: I'll post the state by state totals later on but the results without a threshold are Clinton 270, Trump 264, Johnson 2, Stein 1 and McMullin 1. With a 5% threshold, its Clinton 272, Trump 265 and McMullin 1. Only one area gives all of its EVs to one person (DC; indeed Trump would fall below a 5% threshold although its academic when you only have three electoral votes); everywhere else splits. Some interesting results which show the disadvantage of PR with small number of seats: all of the three-EV state have to split 2/1 even where there's a tight margin, which Rhode Island is 2/2 despite Clinton handily winning.
Those aren't the numbers I got. I don't think you're awarding the two-vote victory bonus, as there should be quite a few more 100% states if you do. It changes the calculation substantially.
