The anode rod is what really is staving off interior corrosion......powered anode rod.....ehhhh.....maybe.
A few suggestions for long water heater life:
1.) Yearly, use the bottom drain on the water heater to flush nasties that settle on the bottom. Do not turn the water heater feed off or the power, just hook a hose to the drain, and under pressure, flush it out. a minute a year should be ok.
2.) Water quality dependent........check the status of the anode rod. They are the sacrificial goat, and once they are eaten, the next thing is the tank..........3 years is what I recommend as the first interval, unless your water is bad. A little penetrating oil before hand helps with the removal. No need to drain the tank 100%, just a little.
Beyond those two things, it is up in the air.