Mechanically, unless mandated otherwise each waypoint is considered a 30 mile journey from another. They can be less, but they can’t be more. So if something is ten waypoints journey away it is no more than 300 miles for a Creation-born who just wants to walk it without dealing with that fancy metaphysical bullshit.
Note that Pure Chaos has no waypoints. If you find a waypoint in Pure Chaos, you aren’t in Pure Chaos anymore, you are inside an Unshaped. However, Creation-born in Pure Chaos become a waypoint, a fixed reference point. Before the Balorian Crusade the only Wyld was Pure Chaos, and the only Fair Folk worth counting were Unshaped. There were an infinite number of Unshaped, none of which overlap and all of which counts as at least one, and probably many more, waypoints. Each waypoint is 30 miles across, maximum. So the Wyld has a “size” which variates from ∞x30 miles to ∞x1 ‘instant’ in volume.