Great suggestion @Katie! Electric baseboard heaters are pretty simple to install, not very costly, satisfies lender requirements AND you never have to turn them on! I have done this to get around the absence of heat source and to satisfy requirements when a pellet or wood stove was the only source of heat in a property.
Unless you have a local bank/credit union who will hold the mortgage paper and not sell it on the secondary market it is unlikely that you will find financing without a permanent heat source. I have ran into this before and electric baseboard seem to be one of the best options. Inexpensive and inobstrustive....they accomplish the financing requirement without any need to operate them occassionally to ensure the systems are working properly.