Peace of mind?
Buy a generator.
Mine’s in the barn and backfeeds the house thru the welder socket.
Yes; I DO make sure to disconnect from the grid before connecting it all up. A plug was a LOT less costly than a change over switch. And with 50 amp breakers on that welder curcuit; I can run EVERYTHING in the house except the electric dryer, stove or oven. (If I need those; I make sure enough other things are disconnected.)
Buy a generator.
I have 3 gens for backup.