I finished the large-print layout today, huzzah! I'll have to wait on the new cover, but at least I know that will be easy to do.
And the proof came today! Well ahead of the estimated arrival time. It looks very nice, I'm quite happy with it--and that's a good thing, because it would have been a real pain to have to find another print-on-demand publisher.
ETA: I should note that I'm happy with what CreateSpace did. But I'm thinking of changing the font. Also, I was considering dropping the size of the font a point for the new layout, but looking at it--no. It's funny because I've printed it out at full size and thought it was mighty big, but looking at it in book form--no, it shouldn't go down another point.
EATA: The actual laying-out process added four pages this time. Last time it added six. I believe I had five pages before I hit CreateSpace's maximum page count if I used 23-point line spacing, so I must concur with my earlier opinion that that was simply cutting things too close.