GPU’s are designed to run at 100% usage. As long as their are no other limiting factors then 100% gpu usage could be for example 140fps @ 1080p or 60fps @ 1440p is still the gpu working at 100% utilisation.
Their 2 things that kill electronics, besides dropping it in water!
Well their actually 3 the normal deterioration of components over time.
For the Heat they will thermal throttle down when it gets to hot. I always use MSI afterburner on every PC I build for myself, friends, or customers. Since most of todays cards the fans don't even kick in till like 60C I will set a custom fan curve all you need is 2 points. I use 50C= 20% and 70C =100%. Having the fans kick up to 100% at 70C helps keep the temp down and reduces the chance of thermal throttling.
This will increase the noise level but I rather try to keep everything cool. You will need to check the box to make it active when the PC boots.
For the voltage just leave it alone and your fine.
Overclocking a video card I never recommend this since it usually requires add more volts. About all the aftermarket video cards are pre overclocked from the manufactures some have more headroom than others. In general your not going to get a lot of performance increase anyhow. If you got a 10% overclock you went from say 100FPS to 110 FPS is that really worth it?
A graphic card can last a decade or more. When do you think you will upgrade? Even if there is a significant life reduction (not that I'm claiming there is); would it matter if the 15 year lifespan is cut to 12 years?
I suspect most GPUs die from fan failure in all honesty.
Are you planning to use that Graphics card for 15+ years? I found a computer in the attic in my new house that's 15 years old, who knows how long it'd been in the with the constant heat and cold since I live in upstate newyork, meaning temperatures well below zero for months, and temperatures up to 100f in the summer and it was still functional. Just saying if an igpu can withstand that It should be able to withstand higher resolutions. Unless you have capped fps that you're easily hitting then it wouldn't make a difference. But a graphics card as others have said are designed to be fully utilized. My dad also has had a gpu in a computer that has been running since it was built 10 years ago. I got a fifteen year old gpu that still works, It's not even pcie x16 haha!! You also see arcade machines from the 80's and even older that still function. Computers seriously last a crazy long time as long as you take care of them properly. You have NOTHING to worry about by using a higher resolution, the only thing a higher resolution display burns through faster would be your wallet haha! Guess what, this will sound CRAZY but when I'm gaming my gpu is under FULL LOAD (not really crazy at all), but as long as I take proper care of it and make sure it isn't overheating and replacing old fans and thermal paste when it needs it, it could last 10+ years with ease.