He is 100% safe in CO & VA. He is 95% safe in ME/NH/MN, the only thing that could cost him those states is if the third party share exceeds 2016, which is unlikely imo. While I wouldn't describe it as safe, NE2 is very likely to to remain with Biden. In the rest of the states he has a decent chance to lose.
This is a good take, but he could lose states like ME and MN, if Trump targets them but Biden ignores them.
I am sure they will both fight for PA which is crucial, but Biden needs to be careful not to ignore certain states.