I also prefer to run Nginx as vanilla as possible, but having automatic renewal of certificates is something which is really nice.
I looked around at some of the more popular solutions, but didn't like the mounting of the docker socket required by [acme-companion][1], or the lack of bootstrapping capability of [nginx-certbot][2], so I made [something][3] that solved both of those issues. A self contained Docker container that is able to populate the certificate request form what you write in your Nginx configuration files.
Please check it out if you have time, and I will gladly take any feedback if you have any!
How I solve this is that I deactivate all configuration files that have missing certificates, and then reactivate them again after the files have been created.
[1]: https://github.com/nginx-proxy/acme-companion [2]: https://github.com/wmnnd/nginx-certbot [3]: https://github.com/JonasAlfredsson/docker-nginx-certbot