If the case gets too hot and you’re not already using the liquid cooler for the CPU, you can get the video card with it integrated for roughly the same effect as if you’d had it on the CPU instead of the GPU.
But it won’t decrease the internal temperature of the case if you mount it in a typical fashion: it’ll just keep the GPU itself cool in your hot case, potentially making the CPU fan do more work.
If you have a tiny case, you could look at doing something weird like mounting the cooler outside of it.