I decided to challenge myself, to see if I could get n8n working on FreeBSD. It was surprisingly easy, and this is all that was required (for me at least).
# update the system
freebsd-update fetch
freebsd-update install
# install node and npm (and verify)
pkg install node16
node --version
pkg install npm
# install n8n as non root
npm install n8n
And I ran n8n start --tunnel
and I was off to the races.