Strongly inspired by the current thread Are there necessarily always at least two points where the Earth's magnetic field is vertical?, this is the opposite question:
Is there necessarily always at most one point (on Earth's surface) where the Earth's magnetic field is directed vertically downwards?
The English Wikipedia page North Magnetic Pole currently says:
The North Magnetic Pole is the point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downwards (in other words, if a magnetic compass needle is allowed to rotate about a horizontal axis, it will point straight down). There is only one location where this occurs, [...]
(emphasis mine).
Of course the Earth's true $B$ field is far from an exact dipole field, see e.g. these diagrams.
Can it not occur that there are two distinct magnetic poles in the Arctic, say separated by 100 kilometers, where the inclination is exactly +90 degrees?
Are there any geometric, electromagnetic or geophysical "laws" preventing that? I cannot think of any.