Work out what the saving actually is before treating it as a selling point. A gap of two percentage points on a $300,000 balance is real money, though Canadian fixed rate mortgages compound semi annually, so the monthly difference is smaller than a naive calculation suggests. Where the loan was insured through CMHC, Sagen or Canada Guaranty, that coverage stays attached to it. A benefit ending in fourteen months is worth far less than one running four more years.
The mechanics limit how often this works. The buyer must qualify with your lender under the same stress tested standard as any other borrower. The balance rarely matches what the buyer needs, so the gap is covered with cash or a second charge at current rates, and releasing the seller from liability is a separate request that is not automatic.
It also has to be arranged early, because lender approval takes time and your possession date does not move. Treat it as one feature of the property rather than as the price. Joel Dyck's hand-reviewed valuation prices the house on its own merits first, then advises on whether the financing is worth marketing alongside it.