For long rides, I like to pack my own protein powder, which I'll add to an orange juice from a gas station. I've tried the little Ziploc baggies that are wider than they are tall, but the problem is that the powder doesn't all go in the bottle :-). I've packed a collapsable funnel, but that just gets annoying.
Trying to find a tall, narrow bag whose circumference when you unzip it is smaller than that of the typical Tropicana bottle. Something like this, but not 3" wide by 20" long :-): https://www.royalbag.com/3-x-20-2-Mil-Clear-Reclosable-Bags-Hang-Ho.... More like 1" wide by a few inches long.
Aldi's house brand "Boulder" has 80count packages of 3 1/2" x 5 7/8" snack bags that are a mite bigger than what you're looking for, but are pretty handy. They are marked one cup and are sturdy enough to be used multiple times.
They are basically these
The other weekend I had a takeout meal from Publican that came with a pickle spear in a plastic zipper bag that is exactly what you're looking for. So I know they exist.