Although you are quoting seat tube lengths, you are actually comparing top tube lengths when looking at frame sizes, right?
If you do decide your current frame is too long, don’t limit yourself to just looking at this modern fashion for sportive-labelled bikes. Lots of “normal” road bikes have long head tubes and are available in a length of top tube that will fit you, and they tend to be a good bit cheaper, particularly in old stock (as MAMILs have bought up all the 2012 and 2013 stock of anything with “sportive” stuck on it.
E.g. I just got my wife a 2011 Giant TCR from Wiggle. Loads of money off RRP and has all the right dimensions for her that the supposed womens-specific, sportive bikes have.