Yeah, when I bought my 1070 I researched to find what models had high quality quiet coolers and that came with Samsung memory which overclocks really well, Micron as I think you are finding is much more limited, if it is any consolation, memory overclocking brings much smaller performance gains than overclocking the GPU.
To answer your question, airflow is often overlooked and is an important factor when you look at whole system performance, suffice to say, heat is never anyone's friend. Bigger cases tend to have more options in terms of airflow but there may be ways of improving what you already have, maybe investing in better quieter fans with improved CFM, making sure for example that you have extraction at the back of the case and decent airflow into the case, wherever depending on your current case you can position your fans.