If Biden wins NE-02 and ME-02 then he only needs to win Michigan and Pennsylvania in order to reach 270 electoral votes.
It will be tough for Biden to make up a 10 point deficit in ME-02. I can't begin to think how the country will react with a likely/significant Biden PV lead and a 269-269 EV tie.
Trump already swung it from +10 D to +10 R between 2012 and 2016. It could flip again, especially considering that ranked choice is now a factor that already gave the Democrats the seat in 2018. If Trump is really as unpopular in Maine as polling suggests, it could happen. Although granted if it does, Biden has probably already won the election and the NPV by a decent margin. It's unlikely that ME-02 flips before Wisconsin, Florida, Arizona, and North Carolina. But I could maybe see it flipping before Ohio, Iowa, Georgia, or Texas. Although the former two at least would probably be very close, because if Biden is winning ME-02, that's probably a sign that Trump's gains in WWC support from 2012 to 2016 have effectively reversed. Which would mean an electoral collapse for him.
The scenario in which the ME-02 delegate is the deciding factor is very unlikely, to say the least. But still the existence of these competitive districts in NE and ME gives me anxiety because they do increase the likelihood of a 269-269 tie, or even Trump winning with exactly 270 votes. These would be nightmare scenarios.
