Ashley - I've had 2 different quilting frames and you DO leave them up. So far I haven't found one that would adjust sizing easily. Think about it -- they're a HUGE machine, going 1000sss of stitches per inch...they need sturdy. A frame that would break down in size easily would be flimsier. Course, I could be proven wrong!
As for 20 by 20 -- yes -- I'd LOVE to have that size!!!