Hi
1. Note that if you drop the 2nd semester, and are no longer "actively studying" for 90 days, IRCC may cancel your study permit.
Invalidité
222 (1) A study permit becomes invalid upon the first to
occur of the following days:
(a) the day that is 90 days after the day on which the
permit holder completes their studies,
(b) the day on which a removal order made against
the permit holder becomes enforceable, or
(c) the day on which the permit expires.