Look at reverse proxy instead. While you can do what you're after with DNS, a bunch of the reverse proxy systems will automatically deal with SSL certificate, and there are even a couple that eliminate essentially all configuration outside of your docker file. Like, add a new docker and it automatically configures appName.domain.tld with SSL assigned. And if you ever decide to expose that address to the Internet, reverse proxy makes that simple and provides some security options as well.
I use Caddy for my reverse proxy running from my OPNsense firewall, but if you want the automation with docker there are better options.
Totally agree. My best trip to date was only planned as far as the hotel of the city we landed in. Even with an unexpected traumatic injury, my partner still agrees it was our best trip. We could stay longer in cities when we wanted to, and leave cities as soon as we felt bored. Compared to other trips where we'd already have hotels booked and felt obligated to leave and stay on those schedules. The worst case was a city hub approach, where we were anchored to an expensive AirBnB. Two day trips in different directions both left me wanting to stay at those destinations.
It's probably a bit more expensive but even if it was 50% more, it was worth it to me at that stage of my life. Probably more like 10% more. Just need to be mindful for some things, there are absolutely places where some days/weeks have no vacancies across a region. Also seems like way more places post COVID require booking in advance, haven't traveled since then but I've heard it makes this approach much less feasible.