[INTPenis]

The key here is console access.

I have an OpenBSD router at home and the only negative part is about once every two years when I feel the need to catch up on the latest release.

Because then it needs a null modem cable and direct access.

So when someone is selling remotely managed OpenBSD VMs my natural question is how to do release upgrade.

[sedachv]

You can do unattended upgrades using autoinstall(8). There is a handy script for patching bsd.rd with a configuration file for the update process: https://bitbucket.org/semarie/upobsd/src although there should not be anything to configure on most boxes (maybe you want to deselect the X packages for your router).