I finally got around to buying a generator and setting the house up for it. I bought a Champion 100297 dual-fuel portable generator. On propane, it is good for 30 amps, which meets my maximum load requirements. Lights and electronics are only about 5 amps. Fridge is another 4 when it cycles on. Well pump is 6 when it cycles on. Water heater is 20 when it cycles on. So basically the only thing I need to keep in mind is what else I have powered on at the same time as hot water is being used. I can't be taking a shower while the garage doors are opening for example. All the lights inside and out are LED, which helps a lot. It will also run my portable air condition (thing with the ugly hose you put out a window). It will probably handle the central air conditioning too as long as I keep the water heater off. I didn't try it, and I may need to put a hard start capacitor on the compressor to get it to work.
I have two 100 gallon propane tanks, and had them put in a quick connect hookup I can plug the generator into. I also had them put a quick connect around on the patio for a BBQ grill. The tanks also feed the direct vent gas stove in the lower level. The gas stove is my heat source in a power failure, since the primary heat source (electric heat pump with electric auxiliary) is way out of the question. The electric auxiliary uses 44 amps when it kicks on. So that will stay off and the gas stove will provide plenty of heat.
Based on the propane consumption math, I have 7-12 days of fuel for heat and power. 7-12 because it depends on temperature and how many hours per day I run the generator. In the spring or fall when neither heat nor air conditioning are needed, that stretches out to two weeks and change. I would always estimate on the lower side of that, and that always assumes starting from full tanks. I plan to make a call to the propane company in advance of any forecasted blizzards or hurricanes to make sure I'm topped off.
To connect it, I put a new 240v 30 amp breaker in the panel, and a weatherproof generator input (L14-30) box outside. Which is right next to the propane hookup, which all happens to be right where the electrical service and breaker panel are located. Conveniently enough, that side of the house has only one window up high and is otherwise a big brick wall, which helps a lot with the noise. There is a UL listed interlock kit which I just ordered (https://www.geninterlock.com/product/siemens-murray-generator-interlock-kit-200-amp-panel-transfer-switch/). It interlocks the generator breaker and the main breaker. So the generator breaker cannot be turned on until the main breaker is off. And you can't turn the main back on until the generator breaker is off. I installed all this myself (with my dad helping out over the weekend), and is actually all legit and up to code.
I have it strapped to a pallet, which I can truck between the garage and the other side of the house with the pallet forks on the 1026r. And the 1026r provided plenty of scene lighting to get everything hooked up. For storage, I drop the pallet onto a furniture dolly so I can roll it off to wherever I want it in the garage. I'll put the wheel kit on it later so I can take it to a friend's house if needed. The cable and propane hoses bungee corded to the generator frame so I don't lose them.
I ran a full load test this evening, and it performed flawlessly. I maxed it out at 30 amps to see what it would do and it didn't even flinch. Ran it at about 25 amps for 30 minutes, and 5-10 amps for another 30 minutes. All in all, I couldn't be happier with this arrangement. And it cost less than half of what a permanently installed auto start / auto transfer would have cost. As a bonus, I can take the whole thing elsewhere if someone else needs to borrow it.
To-Do: Make a little roof and maybe 3 walls on the pallet to keep the generator dry and protected when it's out in the yard.