So I have an upcoming booking SYD-CPH that I used 148k KrisFlyer points for. The reservation was made May 9, 2018. If I cancel the reservation today (March 10, 2019) and pay to have the miles deposited back into my account, when will the miles expire? (1 year from today's date?) ... also, to keep the 148k points active, can I just fly a United domestic flight within the US and have it credited to my KrisFlyer account to keep the points from expiring and last forever?