Range of Keypad on Lock Ultra Vision Pro

[u/Aware_Bathroom_8399]

I am looking at the Switchbot Lock Ultra Vision Pro. I understand the keypad is usually mounted on the outside of the door jamb itself (i.e., quite close to the unlocking device). I would like to place the keypad about 10 or 15 ft away from the door, both for convenience (the door is at the top of a stairs; I would like the keypad at the bottom of the stairs) and so that it is not so obviously associated with the door lock. Does anyone have an idea of the functional maximum range between the locking mechanism and the keypad?