Install FreeBSD as per your requirements.
freebsd-update fetch install
portsnap fetch extract
As you can read in the comments, it is good to know that you only have to “extract” the ports tree once and for every subsequent update to the ports tree, you should only run it with the “update” command as shown.
portsnap fetch update Recommend scheduling with... portsnap cron update
… which will sleep rand(3600) seconds then fetch….