I don't agree with the suggestions to break this up into quatrains, or longer stanzas. It's just fine as it is - in one piece, ... rather like a pane of glass, in fact.
I've also changed my mind about wanting more at the end... I'd now like a bit less!
I think it would be better without Or let fly off stale air no space should save
, thus finishing with the stronger couplet:
I never could control the aperture
Of this transparent thing amid the stir
Of wind and hand; it doesn’t easily hold
The warmth I want, or draw the breath I crave,
Or stand against the weather—battened, brave.
I said earlier how much I liked this poem and I still do.