We'll find out soon enough about how accurate the polls are. It is worth noting that for Trump to win the polls don't just have to be wrong in Biden's direction, they've got to be slanted by a lot.
If polls are off by four points, Biden would still win Michigan, Pennsylvania, and Wisconsin.
Polls could also be off in the other direction. There is the possibility of record turnout, which makes adjusting for likely voters difficult.
https://www.theguardian.com/us-news/...-voter-turnout
We might be looking at an election map where Biden wins Texas, Georgia, Iowa and Ohio, with South Carolina, Alaska and Montana too close to call.