If all of the “toss up” states go to Trump, he still needs Pennsylvania, or Michigan, or Wisconsin plus Minnesota. I consider each of those completely doable.
The big thing is that Trump needs to go for the win, not to humiliate Biden. There is no point in contesting states that are out of reach (NJ, CA, OR, MA, MD, HI, etc.). President Trump should challenge in multiple states that are at least in play (anything “leans D”), but he needs to go all out to defend every state that is only “leans R”, plus all out to win your toss ups and the four “leans D” states that are seriously in play.
I think he should do a fly in to Delaware. I know it’s Blue and Biden’s home state, but Hillary won by 50,000 votes with another 20,000 going 3rd party. Just a little tweak and maybe make Biden’s team worry.