Most days managing five units are boring, which is the goal. Here's roughly what an ordinary one looks like.
Morning: a five-minute check that rent came in for the units due that week. Not a mental note to check the bank later, an actual look, because "I'll check later" is how a late payment turns into a late payment nobody noticed for ten days.
Midday: a tenant texts about a dripping faucet. It gets logged somewhere it won't get lost in a text thread, and either handled that day or scheduled with a plumber, with a note on when it's expected to be fixed so nobody has to ask twice.
Afternoon: nothing, most days. That's the actual win. A well-run small portfolio doesn't generate constant fires. It generates a short list of small, trackable things, and the work is making sure none of them get forgotten, not putting out flames.
Evening: maybe a lease renewal is coming up in 60 days and it's worth deciding now whether to offer it, rather than finding out with two weeks left. That decision is easy when the date is sitting in front of you. It's a scramble when you have to remember it exists.
Self-managing five doors is genuinely manageable as a side effort. What makes it manageable is never having to hold the whole list in your head.