Before we get started, we'll grant that Trump heads into the day a decided underdog. And for the sake of argument, we'll assume that races that haven't polled competitively won't suddenly flip. If a clearly blue-leaning state like Minnesota, New Mexico or Virginia goes for Trump, the polls were very wrong and Trump has many paths to victory. Conversely, if Trump loses a red state like Arizona or Georgia, he's almost definitely going to lose.
In all of these scenarios, each of those states are off the table, and Florida and Ohio are considered must-wins for Trump.
1) A fast East-Coast start
Florida + Ohio + North Carolina + Iowa + New Hampshire + 7 electoral votes
This is the most plausible route because it goes through the most competitive states.
2) Keystone State game-changer
Florida + Ohio + Pennsylvania + Iowa + 6 electoral votes
If Trump pulls the upset in Pennsylvania, his paths to victory increase significantly.
Florida + Ohio + North Carolina + Iowa + Colorado + Nevada = 274 electoral votes
Trump's odds don't look great in Colorado and Nevada, but if he's stronger than we expected west of the Mississippi, here's the path:
Florida + Ohio + North Carolina + Iowa + Wisconsin/New Hampshire OR Michigan = 273 or 275 electoral votes
Trump is even less likely to pull off upsets in Michigan and Wisconsin, which have only come into play in recent days. But if he wins either of them, things are looking much better.