Shanghai Disney cost $5.5 billion which is in line with an inflation adjusted Epcot ($1.4 billion in 1982 is about $5 billion today).
So maybe $20 billion total for the 4 parks, another $1 billion total for the 2 water parks (Volcano bay was $500 million), another $5 billion for Disney Springs, and maybe $30 billion total for the 30 resorts… conservative estimate of $56 billion total, less than the Fox deal. Even at nearly double that estimate they could theoretically afford it at $100 billion.
Possible but unrealistic in any way since WDW is already built.