I have back-up window units out in the shed for that reason. When a hurricane shuts down the power for a week and it's 95 degrees at night...I have my trusty window unit cooling only the bedroom with my propane fueled generator. I've modified the window and AC so that it is an easy 'four bolt', wing nut installation. And, I have two AC units and two generators.
I actually thought about that as a backup plan — go buy a window unit. But we got it repaired in about 8 hours, but out-of-pocket. The deductible on the home warranty is up to $100 and it cost $224 to repair, so that extra $124 wasn’t too bad. If I had had a spare condenser on site I could have done the repair myself — it’s a real easy job as long as you discharge the condenser properly and don’t electrocute yourself!
I bought a spare condenser to have on hand for the future.
I have a car with AC that can take me to someplace more comfortable if need be. Or I can just take a drive.