The longer part of this is Milano-Bologna, where the old or new lines are mostly side by side and its flat & uninteresting.
Blg-Fir. has the oldest and later old line-one can still travel via the very old line, with several changes and if having lots of time-it will not connect smoothly.
The ´newer-old´ line, used by the diretti etc. is also a large part in tunnel, though less as the newest HS-line.
So if having time and willing to do with the more complicated booking (no through ticket) I support above 30907 and go along the costa with change in Pisa-
Oh-its IT, so do not worry if times etc for jan ´25 are not listed yet-it wont sell out weeks before and you may even think of it as be lucky if one can get to see times etc online a few weeks ahead. It also wont be drastic different as compared to tomorrow. And JAN=short daylight, so if you cannot do it mid-day, then it will be dark anyway and hence hardly matter how you go as for sights!