I would say add an extra fan or drop the room temp to 70. If you drop the room temp to 70 the leafs should stay in that size and maybe get a little bigger. It shouldnt matter if they get a little bigger , your plants are nice sizes and nice green. They are all looking pretty healthy so, I would say just drop the room temp to 70 if you can, but keep your fan on it too so the plants will be around 67-68.