I just want to point out this guide uses many of the same tasks I use when migrating websites between servers while minimizing downtown.

- reduce dns ttl (if not doing an ip swap)

- rsync website files

- rsync /etc/letsencrypt/ ssl certificates

- copy over database (if writes don't happen often and database is small enough, this can be done without replica, just go read_only during migration)

- test new server by putting new ip in local /etc/hosts

- turn off cron on old server

- convert old server nginx to reverse proxy to new server

- change dns (or ip swap between old and new server)

- turn on cron on new server