OK, I used "zero lift" to make it clear why the phrase "CP moves to infinity" is used. Yes, in practice you don't get actual zero lift at a stall.
To answer the question, though - the CP is an artifical construction and does NOT represent the actual forces on the wing; it's an attempt to simplify a very complex force/moment situation into a single point force. So yes, the CP, being simply a theoretical device, is NOT constrained to lie on the wing.
If you prefer, take a cambered airfoil at the zero lift (attached flow) AoA. It almost certainly is generating a pitching moment. It has no lift. Therefore, CP either off the front or rear end of the wing, at infinity.
The phenomenom of the lift increasing again after the lift-loss at the classical stall AoA is generally associated with vortical flow from either the nose (weak effect), leading edge strakes (potentially powerful) or a sharp and highly swept leading edge. A more "normal" wing planform/configuration will not recover significant lift post-stall, but simply add more and more drag as the AoA increases.