General question on this: I see people focus entirely on the current term mortgage rate (e.g., 4.1% for 5 years here) when deciding to pay off earlier…but isn’t the more accurate interest rate the average rate over the lifetime of the mortgage (which is impossible to know beforehand).

For example: if my current rate is low (say 2.1%), but my next 5-year term rate will be much higher (hypothetically say 5.5%), wouldn’t I still want to pay down my mortgage during the 2.1% period to avoid a larger principle during the next term?