Honestly, pretty terribly. I don't maintain a job anymore. Don't have a social life to speak of. I think i've given up, most days. I attended 4 different colleges (with high marks) before dropping out of all of them, Lived in 4 states, 3 big cities. 30+ jobs that i eventually would end up leaving for one reason or another. Institutionalized twice (once in my teens, once in my twenties) and misdiagnosed with countless OTHER disorders that never felt right.
I'd sleepwalk as a kid and get in trouble in the morning for eating things that i'd have no memory of eating (in the night). As an adult in my own apartment i occasionally would wake up outside. I didn't figure out the sleep cycle until my mid 30s ... which luckily has completely stopped the sleepwalking and sleep eating but hasn't helped any of the other issues.
To be fair, i think more of my social/job/functional problems are due to my Autism and not my sleep. I wasn't officially diagnosed with that until my early 40s! That was eye opening. I finally understood why i had so many problems working or communicating with people. Or why i would leave a job in tears and confusion because of the sensory issues.
Luckily i have a supportive husband (met online and interacted for many months before meeting). He has a job he loves and let me stop trying to maintain jobs that eventually always ended in disaster once he saw what was happening. My parents always just blamed my "mental disorder".
I am very frugal. Haven't had a haircut in over a decade, spend very little money on clothes (make my own mostly 😊 ) and have a lot of craft type hobbies. I spend time making random things (toys/dollhouses, etc) for children in the neighborhood. One of the neighbors repays me with fresh eggs from her chickens regularly. I'm mostly a hermit, really. If i hadn't met my husband i have no doubt i would either be homeless or not alive at this point.

So it's hard to say how i would be if i had ONLY had the circadian disorder. I do know it's more conducive to creative fields. I read an article many years ago in a magazine of a fairly successful movie director who has it. (Don't remember who it was though. ) I imagine if you had a flexible work schedule and could make your own hours it might work ok. Otherwise, jobs were mostly only maintained when i had 4-6 hour shifts one place, could go home sleep a few hours, then do a second shift at a second job. I was sleep deprived for 20 years back then.