It sounds like you have a heavy duty door lock to be very secure, but you are essentially trying to backdoor all that security with a new internet-connected thing. An adversary only has to break the weakest link here, rendering the physical door lock obsolete.

If you are just going to have some digitally-connected device ultimately controlling access to the house, I'd go with just some standard door lock that does that (i haven't used em but they exist). The physical lock on those is surely less what you have know, but with your proposed solution the physical lock probably isnt what people who crack anyway.