Like others in this thread, I've found that I don't use a whole lot of on-phone storage. 19.96GB currently on the 64GB iPhone 6s+ I got a year ago. Never a problem with my 32GB Nokia Lumia 920, which gathered stuff for 3.5 years. I tend to load things on my phone then delete them after use, particularly videos and audiobooks, and I periodially offload and archive photos on a pair of mirrored 1 terabyte hard drives (special memories go to the cloud as well). So a 32GB SE would have been fine had I encountered a deal on one before the 64GB one I bought the other day.
But that's me. If there's another iteration of the iPhone SE and Apple sees a demand for 256GB versions I think it likely that it'll happen.
