Pennsylvania

Current total votes: 5,622,641 at 64% reporting / 36% uncounted [7,646,791 total votes extrapolated].

Currently:

[Trump: 3,034,309]

[Biden: 2,522,852]

That means there are about 2,024,150 votes that still need counted.

Trump is currently leading by 511,457 votes.

Which means Biden needs 511,457 of 2,024,150 to break even before any other are counted.

That leaves 1,512,693 to share between the two.

Half of that is 756,346.5. +/- 0.5

So of the remaining 2,024,150 votes, this is how many would be needed for Biden to win:

[Biden: 511,457 + 756,347 = 1,267,804]

[Trump: 756,346]

That would bring the grand totals to:

[Biden: 3,790,656]

[Trump: 3,790,655]

… with Biden winning by one vote.

That means Biden needs 62.6% of the remaining votes to have a chance at overtaking Trump.

It isn't IMPOSSIBLE but it seems rather unlikely.