I've been running a synapse server for a few years using https://github.com/spantaleev/matrix-docker-ansible-deploy
I'd highly recommend the above Ansible playbook as it makes it easy to manage not only synapse but also to manage a bunch of bridges and bots if you have the need for them. I have a bunch of rooms that are bridged to Slack for my bozo friends that refuse to use a cool open-source alternative.
I regret moving my phone number to Google Voice because at this point I fully expect Google to someday kill the service.