That's not good to find out when you need it. We lose power a lot here, small town. sometimes takes a few days to get it back after a widespread outage from a big storm. That's what turned me on the the f150 lightning when it was first marketed. Then the dealers all tacked on 20k to msrp so i walked away and got a gas job v8. Our backup plan is our camper. it's in the driveway and the frige runs on propane. i've used it about 20 days so far and it's still 3/4 full on this tank. Should last a long time to save our core food and give us a 'pot' to use for a bit if necessary. The generator can run the a/c too, but we haven't really had to use it..... and don't want to. In my future, we're going to upgrade the battery bank to Lifepo4 and get a few hundred more a/h's in there to run things. I have a 200w solar brief case which keeps the lead acid topped off for our limited use (mostly running the water pump).
I look forward to a better option to get a truck and a home batter backup in one soon. The Sierra EV is just too much money for me to justify right now.