Just leaving a comment here: there's no need for sleep to be in 8 hour long sessions.
What i mean is that You could sleep around 6 hours, wake up, do your stressful activities, sleep another couple of hours, more work, eat something, sleep another 6 hours, stress stress stress, eat, sleep and so on, never having "8 or more" consecutive hours of rest.
Ihmo:
RAW: Yeah. You are not forced to have long rests. I can't even find a place where you are required to sleep at all in the first place (obviously common sense takes precedence...) and there are no exaustion levels for "not sleeping" or "not resting" taken into account into the rules directly.
RAI: Yeah. You are not forced to have long rests. You could be functional for long periods of time with a limited (but reasonable) amount of sleep and resting while not having the required 8 hours straight to "trigger" the long rest. This has to be mediated by common sense as always and if there's a person that has a character that, by inception, likes or needs to rest a lot he better play it grumpy.
RAF: IF you find it fun to have a Sorcerer with 10 thousands lvl 5 spell slots go for it. If you find it disgusting, limit it. In short: As long as for table is reasonable and it's fun, why not? Rules are there as tools. If those tools are not what you need to have fun, make your own tools.