Well, my little corner of Bozeman is a bit warmer today, it's up to -27 F now. We have kind of microclimate here in the Bridger Bowl, a bit less snow down in the valleys and it's slightly warmer than, say, Helena. Still, we had temps around -33 in town and -40 out at the airport. Despite the fact that we routinely get sub-zero temps you still have to respect the cold when it dips down this low. My old car, a Kia Forte I totally two years ago, would start reliably down to -27 F. I got my 2021 Subaru Crosstrek two years ago and this is the coldest it's been since I bought it. While I was a bit curious if it would start I only left the house to walk to the mailbox.

The power is quite reliable here but I made sure to stock up a bit of groceries to avoid having to shop til it's up above zero again. I've got a dozen butane cartridges for my portable stove, a bunch of candles (not that I'd normally use them), batteries for my lights, a powerbank charged up for my phone and of course six Wiggy's sleeping bags just in case.

This year I put together a furnace power outage kit, consisting of a 120V three prong pigtail, a 1000W inverter, some wire nuts and some 12VDC battery cables.

If we lose power but the natural gas service stays on (easily tested at the stove) I can easily turn off the circuit breaker to the furnace, use my multimeter to make sure the wires are cold, and attach the furnace directly to the pigtail.

We then have a number of options, including a gas generator outside with an extension cord, a Very Large Powerbank (freshly charged), or taking a battery out of one of the cars to bring in to run with the inverter. In that case, when that battery gets low, we can reinstall it in the car and run the car to recharge it.

Perhaps this summer I’ll pay an electrician to install a generator transfer switch.

Important notes: At no point will I make or possess a “suicide cord.” And the furnace will be completely disconnected from the house wiring while the pigtail is attached.

Chaosmagnet, I don't think the furnace will work on a 1000 watt inverter. I'm assuming that it will use 500 to 600 watts running, the starting watts could easily be 3x the running watts. Some inverters have fairly high surge capacity but I usually don't see that in a small inverter. Check it out before you rewire it.

Pigtails are a good way to go for controlling loads. I've permanently installed pigtails on certain appliances so that those loads can be run independently from a generator. It helps with load management, it's only plugged into the generator when you need to use it. I'm able to run everything in the house but the central AC (small window shaker for backup) and the deep well pump on a 3k generator. I back feed the fresh water rv tank for the house water, this works well for the short term.

This inverter is rated for 1000W steady and 2000W starting load, pure sine wave.

I haven’t tried it, but if I calculated correctly there should be a significant margin. We don’t have a window unit backup for the central air, but I can run it off my inverter generator at need.

Sounds like you are good! Hope you don't need it but if you do let us know how it worked.

Definitely! And so far so good :-).

Today it's in the low 40s and rainy. Danged odd! It's going to slick for sure but otherwise we seem to have weathered the worst of it.