I’m not an expert in FA but I would hope (and think) that Penn is considerate of your change in income and will raise the financial aid package.
Without knowing the exact details of your situation it’s impossible for me or anyone else to give you specific advice. I’ll just reiterate that there are certainly outcomes where the cost of Wharton is more than worth it. I imagine others will rightfully point out that a lot of employers hire from a wide range of schools, and your son can be very successful regardless of where he attends undergrad.