It seems like there’s a lot of ways to go about this that may be overkill, so I’m curious which may avoid that.
Low maintenance in this context is aiming for moderate technical knowledge/setup, lower cost, and portability in case you need to migrate your site and so minimal hassle in that process.
Mainly the latter, and you cover the reasons for that, so appreciate it! For a more casual approach (and according to one’s preferences), it sounds like you’d be alright to stick with the subdomain-from-host approach, which is how I was leaning but I wasn’t sure if there might be more to it than that within the more managed hosting space.
If a subdomain from a hosting provider works for your use case, then there’s nothing wrong with that.
I have 10 years of experience making websites for a living for huge tech companies, and even then I still use ec2-[hash].compute-1.amazonaws.com as the domain name for a gaming website I run for just my friends.
If you don’t care about professionalism or SEO then its fine.