While I'd love the solutions you actually asked about, the budget and/or time hasn't been there yet (there are lots of good videos on DIY Powerwalls), but I was pretty proud of my plucky New Englander lower budget solution.

Normally I just ride out any outages, but we had a newborn for this one so that wasn't going to fly, especially if the hype was to be believed. I already had a handful of batteries from the Ego Power tools (could not more strongly recommend), so I ran out and grabbed what was apparently the last Ego Power Station on the Seacoast.

This would have been enough for a radiant space heater or running the toaster oven or even the tankless for some showers. I also justified it with the thought of future camping trips or remotely running my few remaining corded tools.

While there I also picked up a couple of DC>AC inverters so if the existing stored energy did not suffice I could use the rolling generators sitting in the driveway to convert the gas in the tanks.

Failing any of that there is always the wood stove, but I would have had to have moved the Christmas tree and no one wanted that to happen. I also grew up using exclusively wood heat and vowed to not be hauling wood when I was an adult, so avoid it at all costs.

Ultimately we were only without power for a few hours, so didn't really get to exercise the plan, but at least we'll be more prepared for the next time.