Yes, you are right that there's a difference in how the snowbelt vs. sunbelt heat their homes. Part of your solution could be there.
Heating in the snowbelt is almost always a large fuel-fired furnace with forced pumping of working fluid (i.e. forced air). This requires both fuel and electricity, if either one fails, the home becomes uninhabitable -- and that's just accepted somehow. /boggle/
An all-but-lost style is the "gravity furnace" where the heated air is meant to rise by convection, up a carefully designed ducting system. This obviously requires a relatively vertical house and one designed for this. This could work without electricity, but since a forced-air furnace is a drop-in replacement, I'd imagine most have been converted.
Heating in the sunbelt is a simpler affair. You often see all-electric heat, and those are easily seprately zoned, so you only heat the spaces you are using. You often see all-gas heat, by which I mean a gas furnace that does not require electricity. For instance, my home is cozy warm in a power outage. You also see forced-air systems, but the motivating factor is A/C not heat.
These two ways of thinking are so different that frankly, installers in the snowbelt are not conversant in the sunbelt style. Stores in the region don't even stock the gas furnaces. I'm not even sure city inspectors would allow a sunbelt style.
The achilles' heel of the sunbelt systems is carrying the heat around the house. (sunbelters don't need heat in every room, nook and cranny since pipe freeze is not a big issue). Electric heat can be carried around the house on 12 AWG wire, with cheap $50 Cadet baseboard heaters at point of use (separately zoned too; nice.) But gas-only furnaces rely on convection to carry heat around the house, and that only works with certain topologies.
Another option which is all-electric is a heat pump. Recently, they have been getting quite good. Ground-sourced heat pumps are even better, but rather costly to install. Since they only move heat, not create heat, they are much more efficient than a heating element or burner. You need a unit designed to work in "rather cold" conditions, otherwise it will need a thermal-heat backup, either electric heating elements or gas. In that case I would look at that gas-only furnace.
They come in several types; including floor furnaces (set in the floor with a grating, and I've seen an $800,000 house with one of those!) Or a "baseboard" style embedded into a wall with outlets on both sides of the wall. Or a vertical, up-the-wall "wall heater" designed to reside embedded into an interior wall, with gratings on one or both sides.
The gas wall furnace I linked is typically jetted for either 25,000 or 35,000 BTU if single-sided, or 35-50,000 BTU if double-sided. Like any passive gas heater, it needs a vent more-or-less straight up, and entirely properly built on the outside. You see a lot of negative Amazon reviews from people who have no idea what they're doing and blame the product.
The upshot is, you have a really exceptional home, that deserves a really exceptional furnace. With such efficiency, you are not far away from power-outage resiliency with just a little application of "solar off grid" type technologies to protect essential loads like refrigeration, auiliary lighting, router and tablet charging so you can watch Netflix in your cozy home. However, a balky blower to push air around the house is an impediment to such an achievement.
