I was a bit surprised at the smallness of it once I got it all together. It's still OK, but a bit short/small for me. Now I see another one for sale, just like my present one, but I can tell by the longer head tube (?) that it is at least taller, but would a taller bike also be longer?
Usually, especially in newer bikes. This is called "proportional sizing", and as far as I know, bike frames have been made that way at least since the 80's. Top tube length is actually the most critical dimension in bike fit. You can effectively adjust it a bit with stem length and saddle position, but only within limits, as those tweaks also change the weight balance and effective seat tube angle.