You can try using an Upscaler.

If you have Nvidia, they recently added a feature called 'Nvidia Image Scaling' (NIS).

It's essentially Nvidias own version of FSR, but you can easily get it to work in basically every game. There are guides on youtube on how to use it.

This will let you downscale the game to a lower resolution and then using this scaling technique to blow the image back up to 3840 X 2160 (or whatever your native resolution is) This can drastically reduce the GPU strain, while NIS tries to maintain the same image quality.

There is a little sharpening option within this feature to, which will allow you to sharpen the image if it appears slightly blurry from the scaling. I'd start with that 'off' though and then increase it by 10 after that if you notice blurring.