I don’t get as detailed as you but go on feel. One thing I definitely do is drink HEED no matter the time (with the exception of a 30 minute ride) because I am of the opinion of fueling for the next ride.
Personally, I love HEED because of the complex carbohydrate profile it delivers vs. simple sugars found in other sports drinks. As far as solids, I might do a gel now and again but I find that a banana during long spins does the trick for me (maybe even bread and natural peanut butter prepared in advance).
According to The Endurance Diet by Matt Fitzgerald, all bets are off regarding consumption during training, so don’t worry about gaining weight as you are essentially replacing what you are using.
But then again, nutrition is individual and has a bunch of opinions. Good luck!