Happy to suggest. You're so right, available conditions like window size often need to be given more consideration than our fantasy of what our plant could look like without those restrictions.
I drew lines on your pic where I would cut these stems, for a shorter, rounded & full look.
If this was my plant, I would do this in 2 stages if it is all connected to 1 trunk near the soil. If they are separate individuals, doing in stages would have no benefit. It looks like if one stem was trimmed, the other stem would still be able to get plenty of light for a while. From this angle, it looks like the stem with the white line has the fewest leaves on the lower part of its' stem, so I would trim it first. Once removed, remove any leaves along the lower 6-10" of stem, then stick it 6-10" down into the pot with the rest of the plant so that the whole length of naked stem is buried. I always try to aim for a spot where the foliage will fill a void in the current mass.
Doing it like this means you don't need to try to tend a pot that holds nothing but a cutting, a much more tricky endeavor than getting one to root in a pot with an existing established root system. No reason to not try that, there's no guarantee any method will surely work for any cutting, but if you want to be able to do nothing more than tend the pot in the same awesome way you have been to have such a lovely plant, that's likely to work as well for you as it does for me.
Whenever a stem gets out-of-bounds in the future, you can trim again, and again. If you have fun with it, before you know it, you'll be looking for new homes for some of the babies. ;)