We have a surge protector at the point where power enters our house, and several smaller ones through out the house. These are essential, but don't do diddly for low voltage situations.
Agree, the one-plug-at-a-time AVR's work well to protect the appliances, definitely. They can also fry from too long a period of low voltage (or really big spikes) - all of ours fried about 2 days ago. They sort of commit suicide to save the appliance they are protecting. When they fry they block any current at all from reaching the appliance. In theory all you need to do is replace them.
That's the wrinkle in the sheets.
We could find only one replacement for sale yesterday. Even if we would have purchased 5 or 6 (at a price of $100-150 BZ each), chances are good that the current (pun intended) situation could burn them out too.
Until the present mess is resolved, we were advised to run fewer electronics so less stuff is at risk. The temptation is to just plug in appliances and hope for the best without a high-low protector for a day or two ....... but apparently it's not a great idea just now.