He got his permanent residency? Does he have the condition that you must stay together for 2 years after getting his PR? If that is the case, as long as you say you are still together but you are temporarily living apart because of the job situation, nobody will do anything to his PR. Even though immigration mostly requires and unbroken period of 12 months in order to prove common law for immigration purposes, it is still accepted that common law partners are well as married couples may live apart because of job or related situations. For example, live in caregivers can declare their common law partners on their work permit applications and years later as they have been in Canada working can apply with their common law partners on their applications even though they have then lived apart for years due to the live in caregiver working in Canada.