You could have electric baseboard heaters installed in less than a day, they are inexpensive, but find out more from the lending institution.
In PA, you only have 10 days for loan approval. I guess you may need to work with the seller on this. Tell them that no-one will provide lending and they won't sell unless they put some baseboard heaters in those rooms.
Remember, that the electrical system in that old of a place may not handle the additional load of two baseboard heaters.