While it is not a simulator, you can start with this
roadmap from 538. With PA in the Biden column, Biden is at 278. If you want to give Trump the 20 electoral votes for PA, that would push Biden back to 258. The states they have leaning Biden are:
NE2 - 1
AZ - 11
FL - 29
NC - 15
ME2 - 1
There are also few other toss ups in GA (16), OH (18), and IA (6).
As for your question, if Biden wins FL (and holds on to the states where he is heavily favored and slotted in his column), that would give him 307 electoral votes. So Biden could lose OH and FL and still have multiple ways to still win.