What are the chances of having a clear unambiguous decision in November?

Recently, there has been a lot of speculation about whether Trump will concede to his opponent in the unlikely event that he loses in the electoral college. For instance, see https://www.theatlantic.com/magazine/archive/2020/11/what-if-trump-refuses-concede/616424/?utm_source=email&utm_medium=cr&utm_campaign=oct-cover-prospects&utm_content=20200923&silverid-ref=MzUxMTMyMjQzODM2S0

Obviously if the results are overwhelmingly against him, he will have no choice but to concede. However, if the margin is one state, which had 50+% mail-in voting and did not announce the results until the end of November, all bets are off. I suspect if the election is that close, Biden may not concede either. In fact, Hillary has called on Biden to not concede if the election is close: see https://www.politico.com/news/2020/08/25/hillary-clinton-joe-biden-election-advice-401641

Hence my question: Do you see a scenario in which we may have a clear winner on Election Day?