I have a 3060ti and it already serves this purpose. The trouble is that it does it in summer too.It'll be great having a 5090 during the winter months -- you can use it as a space heater.
Depends on what generation. They tend to trade places on this every so often.If they can come up with a 200W variant that is faster than my 3070, I'll buy it. Otherwise, I'll just wait for the 4070 to start flooding the used market. I may even consider AMD, but I'm not holding my breath. Power efficiency has never been an AMD strong suit. A 200W card from AMD, usually performs more like a 150W card from Nvidia.