Everything I've seen suggests that Plus loans will cover any cost of attendance at a college that isn't covered by other financial aid.

https://studentaid.ed.gov/sa/types/loans/plus#how-much

It is possible to discharge student loans (not just Plus loans) in bankruptcy, but you have to basically prove that you can't survive while still making the payments. I don't know if it is easier to discharge the Plus loans or if they all require the same level of hardship.