That's a valid concern for you where you are.

For me where I am, things are different. We don't get hurricanes here.

Our longest power outages tend to follow ice storms. We need heat because these things happen in the winter time when it's cold outside, and that's dangerous for various human and infrastructure reasons (pipes freezing and breaking).

But I use natural gas for heat and I don't recall ever having a weather-related natural gas outage. So that's helpful. And ice storms tend to happen when it's cold, but not damn cold -- that helps, too.

My furnace uses about 600W of electricity while running. It does not run all the time. According to my charts on a random day/night cycle last February with a high of -8C and a low of -16C, it was running with an average duty cycle of about 30% over that period.

600 Watts × 30% × 24 hours = around 4.3kWh for that 24-hour period, just for heat.

I'll also need to keep the fridge cold, and some lights running, and will surely be getting some use out of a laptop and some network stuff.

A common-enough home battery size is 48v, 100Ah, or 4.8kWh. They cost around $1,000 right now (some more, some less) in DIY-friendly shapes.

As a spitball effort: If I live more-conservatively and dial back the thermostat (it is a power outage, after all), I can probably get enough power to live a productive, comfortable-enough life on one such 4.8kWh battery, per day. Ish. If I'm careful.

So for batteries, alone, I'm at $1,000 per day. I'll need an inverter as well. That can be either minimal or extensively integrated, grid-tied or not, solar-accepting or not, and etc. Let's just pin that at $3000, with the wiring and accoutrements, and assume I'm doing the labor for free.

I'm now at ~$10k to survive a week of power outage at home in the winter on batteries alone. That's expensive[1], yes, but a whole lot less than half a million bucks. A whole lot less than a very nice, installed, low-RPM generator, too. :)

...except, realistically: It's more like $13k for a week, because future-me will surely not be as careful with energy use as present-me suggests that I should be and 3 more batteries adds some safety capacity. :)

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And that can be supplemented. Solar input can obviously be used (if available), but may be limited by winter sunlight conditions and storm accumulation.

Gas-fired generators can also be used. An inexpensive-ish portable inverter generator does the trick well when combined with, say, an EG4-6000XP do-all inverter.

That particular inverter wants to see at least 2 of these batteries connected, so let's play with that minimum: 2 batteries, 1 inverter, 1 generator. ~1.4 batteries worth of load every 24 hours, as with the safe $13k figure above.

The generator can be run pretty hard (it has a continuous max rating for a reason), and it can be run intermittently. The EG4 allows programming of generator input power.

So let's pick a generator: Champion 201509. It can do 7kW continuous, and we'll load it to 75% of that, or 5,250 W. From this 5,250W, it provides for the house's present consumption while it runs, and it restores the charge of the two batteries to 100% SoC[2].

If it is run once per day, it can do this job in about 2 hours and then be switched off until tomorrow.

If it runs like this once per day for a week, I guesstimate that it uses about 11 gallons of gas over this week. That's a very manageable quantity of fuel.

So we're at $2k for batteries, $3k for inverter+stuff, and $2k for an appropriate generator. That's $7k to run ~indefinitely, or as long as I can keep bringing in fuel, with enough power to survive a blackout (with heat, lights, refrigeration, some entertainment) long-enough on batteries alone for the roads to become passable and then decide if I'm making a run to fill up the gas cans with fresh fuel.

Not so bad for a relatively quiet time of living in a temporary blackout, and the house gains a gains a big UPS for some stuff (which is nice). (The installed gear also offers an easy entry into solar power.)

But I'm not in hurricane country. And while I do love me some aircon, our summers are pretty survivable, usually. My needs are not the same as your needs are. :)

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[1]: Except, for the price of this kind of self-sufficiency: Draining/blowing out the plumbing and staying at a hotel or with friends/family for a few days in an unaffected area might be a better option. The cheap portable air compressor I have doesn't leak down at all, so it's always got a full tank of air while just sitting there unplugged. I'll figure something out: Power outages are very quiet, creative times.

[2]: 100% SoC? Yep. It's a temporary blackout where the batteries are operating as a UPS, not a long-term operation where the typical 20%-80% SoC goals are important for longevity. They won't stay at 100% for very long, anyway.