Can you do anything to make power tubes last longer ?

I saw an article about 833A triodes that says they last longer with the cathode run at 9.5 Volts rather than the full 10 Volts, and there is no loss of how they sound. Also, these tubes are built to last because they are used in AM radio stations as transmitter tubes. Running them at 1000Volts on the plate rather than pushing them so hard that they have a red glow spot will make them last indefinitely. The drivers I use are 45 globes that cost about $75 to replace on ebay and they last for years. I keep spares. Some claim that solid state requires less maintenance because you never have to replace tubes, but changing a tube is so simple that finding a bad transistor is far more complicated. Also, if you can use metalized polypropylene filter capacitors in the high voltage to run the tubes, you have indefinite shelf life and better ESR than the slightly cheaper electrolytic filter capacitors on tube amps costing five figures. This is why I build my own tube amps and preamps.  

Some claim that solid state requires less maintenance because you never have to replace tubes, but changing a tube is so simple that finding a bad transistor is far more complicated.

This is true. Across probably hundreds of components I've used in my time in this hobby, once you eliminate simple "replace the bad tube" issues, I've had decisively more failures with Solid-State - and they're far more frustrating and difficult. Especially when the transistors you need are long OOP and counterfeited like crazy.

Bill, there was a lot of electrical work done in your house and still the current is not good enough, especially, as I understand, in summer.

Batteries can limit the dynamics, I guess, but maybe some companies overcame this, I have no idea.

I use old PS Audio regenerator in my system, everything is plugged in it. By comparison, without it the system is unlistenable, and this is not exaggeration. The dynamics too is much better.

I think, wall current is the biggest problem in audiophile world. And increasingly so.

Good tube equipment will last for decades with only occasional tube replacements. The only problem, two problems in fact, NOS tubes will be getting more expensive and more difficult to find. But some transistor equipment is also very reliable, think Gryphon and Accuphase, as an example. If not tubes - that's what I would have.