APK Mirror: https://www.apkmirror.com/uploads/?appcategory=nova-launcher
The Nova Launcher archive goes all the way back to 2012, so that's not a problem.
The thing is, if you install an old version and disable updates, you still depend on the Play Store not to update it. From time to time I manually open the Play Store to force updates, when some app isn't working as it should. So for me at least, it's only a matter of time until I forget about this and update the app.
We could block it from accessing the internet, but looking at DNS queries, this latest version also keeps retrying failed connections every few minutes. There's no way that's good for battery life.
In other words, while I'm sad and this is pain in the ass, it's time for me to move on.
I had similar issues with the latest beta version from Github.
A few years ago, I installed Nova on my parent's phones to work around small text on the stock launcher and to make it easier to move the layout to a new phone. I wanted to replace it with Lawnchair, but the icons freaked out while I was recreating the setup, so I gave up. Octopi Launcher seems to be a good replacement, but they expect new apps to appear on the home screen(s) and unfortunately Octopi doesn't support that, so I'm currently testing Pear Launcher, which is closer to Lawnchair, fairly simple, but stable so far.
I might go with Octopi for myself, but I too like to have new apps appear on my home (so I don't have to go look for them and don't forget to remove what I'm testing), so I'm not sure yet. I like the performance of Lynx Launcher, but it also lacks this feature. By default it also uses a different "layout"... but it's smooth on my phone, there's no BS. A tempting option.
Smart Launcher seems to be very nice, but pushes the premium stuff hard. While I plan to buy/donate to support development of the launcher I will use, I'd like to test things without having a "upgrade to premium" banner in front of me.
I know it's just a launcher, but f me, it's hard to find a good replacement for Nova.