I do the same as OP with my Fedora workstation, which is wait till I have to summon all the available mirrors just to serve me several gigs of software updates every other week.

For my servers I have an ansible script to update most of the machines. I fire that up every start of the month after the automatic backups. Seems like I'm a week late again already. In these I use apt dist-upgrade since that seems more robust, but I'm still to shy to run it in a cron job.