The Debian archive is updated 4 times daily, so I update my system after each Debian update. I do that no matter whether I am working or not.
Packages almost always aren't broken in Debian testing but if they were, a reboot would not fix them anyway.
I restart processes instead of rebooting (using the needrestart/needrestart-session tools). I only reboot after Linux kernel image/module updates or microcode updates, because Debian cannot yet live-update those components.
How do you deal with packages being broken until the next reboot if you do updates during the day?
I don't even update my Arch boxes that regularly and always do a reboot afterwards.