On longer rides I always carry extra isotone drink powder, 3 scoops per serving in a small bag (30-40gr carbs) and you only need water along the way to refill your bottles…
I use 750ml bottles, and can last for 2-3 hours when it is around 20-22C.
Also i take small energy bars with me (Amacx fruit chews), and on low intensity rides i will take 1 every 75-90 minutes…
So for a 6 hour ride, 2 refills of isotone powder in a small plastic bag. and 3-4 energy bars… Does not take much space (fits all in 1 pocket in your jersey)…
Eat/drink well before the start…
And also after the ride, eat and drink to recover…
If i am running short on supplies, coca cola regular and a snickers or other candybar will help a lot.
But most of my 6h+ rides include a coffee stop + apple pie, i can refill my bottles and never come short.
Sistema screw top 35ml salad dressing pots hold 35g sugar and are narrow enough to empty easily into my Elite Fly water bottles. Or use empty hydration tab tubes which hold slightly more.
For rides 3 hours plus I’ll stop for a Lucozade Sport or similar sports drink to refill bottles, something like a flapjack and an iced coffee to have whilst stopped or an ice cream if it’s hot. Maybe a packet of Haribos to stuff in my pockets for the road but generally I try to carry sufficient gels and energy bars for on the bike eating
Except last weekend when, 20 miles in, I realised I’d left them all at home
What if in future you just mix the carbs at higher concentration in one bottle?: enough for the ride, then with each sip of it chase it with some water+electrolytes. Given that sucrose is your thing, I managed to completely dissolve 400g of it into solution & fit in one of the 550mL-ish bottles by Trek. I dissolved into hot water in stages in a large coffee cup, emptied into the bottle with some cold water in there. Refrigerated there was no precipitate, so it was nowhere near saturation. So with a 750mL bottle you should be able to do 600g.
This was my third bottle on an adventure, fixed to the back end of an aero bar stick with a bidon cage intended for a narrow old-skool MTB handlebar. Other two bottles in the triangle were dedicated to hydration only.
Use this system for races with bottle hand out on the fly. But just riding solo find it just mean I need to stop sooner to fill up the carb less bottle again with plain water. Effective seems like riding with 1 bottle and one big energy gel. The 3rd bottle would definitely help with this though.
So a coke or two, a bottle of orange juice, and then to get some food in, a baguette with something low fat!
Some mindset when at cafe, but plus a coffee.
If you have fuelled properly until the stop, the above food plus maybe a banana and one bottle with some carbs should get you home for the final two hours.
I mix 300g sugar in a ~700ml with cold water and shaking. Hot water works better obviously, but I often forget to do it the night before. I like Pepsi and other caffeinated drinks but often the acid bothers my guts. On brevets I’ll carry bags of sugar and mix more along the way. I also put some sodium citrate in my mix.
I have also done this with a bottle of coke. I really, really wish we could just buy the syrups, then reconstitute as we choose!