Why with really good cooling? The TDP is very low on these and it is a breeze to keep cool.
http://www.guru3d.com/articles_pages/gigabyte_geforce_gtx_970_g1_gaming_review,8.html
My pc is now very well cooled, but the problem is the distance from the lowest card to the PSU, the PSU will be drawing all the air away from the lower Card, this is why the dual card is so good.
there's nothing stopping me buying a new case though