Sorry, I have little time this week for my usual suggestion service, but the topic of frosted glass is a (current) FAQ, and even for 3m high windows, builders have already had to experience that not everything you can draw is actually made that way. It is basically possible if you are willing to pay a "highlight" price for it – but for glass (and frames) above 240 cm in height, you will regularly be advised to have two-part elements. I wouldn't want this "choice" between the devil and the deep blue sea either (a cumbersome opening sash or the entire window as a fixed element). Do yourself a favor and consider an uneven three-part division, making one opening sash that repeats the color of the front door. Evenly two- or three-part windows in such cases immediately make the viewer think "that was probably too expensive as a single piece."