From your description it sounds like I can change Cinnamon to something else
You definitely can.
is this fairly straightforward to do?
It ain't bad. However, I would opt for a distro that defaults to the preferred DE. In this case, similarly to Linux Mint, the distro would have to be beginner-friendly, popular, polished and stable[2]. So, IMO, that would be:
- GNOME[3]; Pop!_OS or Zorin OS
- KDE Plasma; Tuxedo OS
- Xfce; MX Linux
Note that there are many other DEs. However, the above mentioned DEs (together with Cinnamon) are the most polished and popular. And while there are many other distros through which you might 'consume' said DEs, the distros mentioned above are the ones I (personally) like to recommend.
- At least relatively speaking.
- Stable is used here in the context of meant to be used without updating for 'extended' time; except for security updates.
- While both default to GNOME, they differ pretty significantly in how they're setup and the associated envisioned workflow.
To be clear; while OP does mention "Fedora Silverblue" to introduce and contrast atomic distros to traditional ones, they only explicitly recommend uBlue images.
And while it's by no means as exhaustive as the ArchWiki or Gentoo Wiki, uBlue's documentation isn't a slouch either; I've seen far worse. If possible, could you name what's crucially missing?