I’d like to use this lock in a door where the deadbolt is installed below the door handle. So there isn’t enough space to install the lock in the normal, upright position. Will it work upside down?
Welcome to the Forum, @ceeskee! 
Have you looked at Is my door compatible with Wyze Lock Bolt v2? That’s probably where I’d start in order to get an idea of dimensions since you mentioned space as an issue. I imagine that it would still work if installed upside down, but my concerns with that—especially on an exterior door—would be that the keypad would be upside down and that the USB-C port for emergency power would be oriented upward and unprotected.
Without knowing more about your particular door situation, I’d probably be inclined to look at different lock options or to relocate the deadbolt to a standard position (i.e., re-cut/drill the door and mortise the jamb for a more typical deadbolt location and patch the leftover existing deadbolt hole or cover it with a plate). If you do decide to attempt an upside-down mount and use, then I hope you’ll share your experience with the rest of the community!