The long middle is where people stop
Novelty gone, end not visible, progress invisible.
Long part-time courses have a predictable low point somewhere past the midpoint. The initial energy is spent, the qualification is still distant, and the work has become routine. Attrition concentrates here rather than at the difficult early stage.
Knowing it is coming helps more than it should. Treating a period of low motivation as an expected phase rather than as evidence of a wrong decision is what gets people through it, and the difference is largely in the interpretation.
A visible record of what has been completed is the practical countermeasure, because perceived progress in the middle is unreliable. A list of finished units, kept somewhere you see it, corrects the impression that nothing is happening.
Reducing the load temporarily is better than stopping. Somebody who takes one unit instead of two for a term usually continues; somebody who takes a full break frequently does not return, because the arrangement they built dissolves and rebuilding it is harder than maintaining it.
There is a further provision worth knowing about, which is what happens to fees and enrolment status if a unit is withdrawn from at different points. The dates that determine whether a withdrawal carries a financial or academic penalty are usually published and rarely noticed, and they matter enormously in a bad term.