We have no idea whether or not W&M would discount/change the initial FA package.
I do agree that FAFSA won’t change their current offer. If dad wants to negotiate the current offer he should engage with W&M now. Re-running the NPC is a good idea.
If dad is going to pay the W&M price no matter the outcome of the negotiation, then OP should pull their other apps/acceptances.
If there is at all a question whether the dad is going to pay, then OP should keep the apps/acceptances open.
Dad is in charge of the money, not OP.