You don't have to enter the passcode every time if you've got a TouchID device. When my new phone shows up, I have a 13-digit code memorized from when I was a kid (long story). I'll input that once a day, and use the scanner to unlock the device the rest of the time.
Really you only need a 6-digit passcode to be exceptionally safe, but it's honestly easier for me to remember this particular code than something shorter.
Does any of that exist? If I have to build that system myself (or parts of it), do you have other suggestions? For the inevitable and completely reasonable suggestion of getting someone competent for tech support: I've tried that too. The competent ones don't last beyond the third visit.
E = MC ** 2 +- 3db