Looking at some of the crosstabs (including that more Republicans took part in the poll), this doesn't look good for Trump at all. If he's losing Arizona by 5 even if it's in the margin of error, then McConnell seriously better be thinking of pursuing the Bob Dole strategy. ("Hey, we know you don't like Trump, and that's ok. Feel free to vote for Biden but you should vote for us to keep power in the Senate so that Biden doesn't have free reign over the government. Vote for us to be a check on Biden.") Granted, we don't know how well that'll work with an incumbent, but at this point, they really need to start to thinking of other strategies than just appealing to Trump.
That actually worked perfectly in 2016. The Dems lost the tipping point senate seat by like 2% but lost the presidency by like 1. If it wasn’t for the Halloween surprise, I could see a window for a R congress but D president though even if Hillary won and it was close, it wouldn’t have been certain. I would also say that if Trump comes within 4-5 points of Biden by Labor Day, I would hope Schumer decides on that strategy too.