[cabmandone]

Wait, you have a dual fuel system that doesn't have a thermostat capable of going to Emergency Heat which bypasses the ODTS and defaults to the furnce?

As for what system, your degree days would probably allow you to go with a high efficiency variable speed system with electric backup staged in as the temp drops below a balance point... but I don't see how that's any less complicated than a Heat pump and gas furnace. My thermostat controls everything. I set the balance point in the tstat, the outdoor temp sensor tells the stat when the balance point has been met and turns the gas furnace on. I'm not sure it gets any more simple than that.