I'm definitely a nocturnal introvert. If it wasn't for having a daytime job I'd be up every night until about 6 or 7 in the morning, sleep til about 1 or 2pm, and then get started again around 3pm, which is what I do on my days off, no matter what my schedule is the rest of the week. As soon as I get a couple days off I revert back to type!
I don't have a problem with isolation. I have a couple of friends and family members I talk to on my terms but I can go several days without interaction with anyone, and my life wasn't significantly upheaved by the pandemic since I was already living in isolation. I'm not bored, or lonely, that's what the internet is for really. I have plenty to occupy my time, and I like my own company. I do like people and my interactions with most people are very pleasant. I just prefer my own company.