It makes sense to have more GPUs than a single one because of losses, the risk is limited with 4 GPUs instead of one, for example the gtx1660 super can cool at 54°C to 58°C, this will simply keep the graphic card alive for a longer time but with one gpu that can do 80 to 90°C anything can happen
I think it's easier to cool a single gpu like RTX 3090, you can also leave the fan variants and go for liquid cooling types, this will keep the high temp to minimum level and thus makes mining experience more enjoyable, less electricity power at higher Hashrates, nothing comes close to this